SunShine Optical simulator User`s manual

SunShine Optical simulator User`s manual
University of Ljubljana
Faculty of Electrical Engineering
Laboratory of Photovoltaics and Optoelectronics
SunShine
Optical simulator
User's manual
Version 1.2.8
(including Optimisation tool, LPIF transform
and 15 ADF groups)
Ljubljana, July 2011
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~ SunShine ~>
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User's manual
Copyright © 2011
University of Ljubljana
Faculty of Electrical Engineering
Laboratory of Photovoltaics and Optoelectronics
All rights reserved.
Ljubljana, July 2011
Preface
SunShine optical simulator is a 1-dimensional simulator that was developed for simulation of
thin-film multilayer optoelectronic structures, such as solar cells and photodetectors. Its main
advantage is related to simple description and consideration of a complex light scattering
process at nano-rough interfaces that are introduced in the structure. Based on performed
verifications on several solar cell structures (a-Si:H, c-Si:H, micromorph (hybrid), CIGS,
HIT and others) the simulator has been found to be a useful tool investigation and analysis of
thin-film optoelectronic devices.
The purpose of this User's manual is to help the user, which has already been acquainted with
the physical background of the optical model used, to carry out the simulations. The selection
and determination of all input parameters is described.
For physical background, the reader should refer to following references:


Presentation on Optical model and input parameters (slides)
J. Krč, “Analysis and modelling of thin-film optoelectronic structures based on
amorphous silicon”, PhD. Thesis, University of Ljubljana, ISBN 961-6371-50-9.
Following the license agreement, Licensee agreed to cite a reference to one of the following
publications:
KRČ, Janez, SMOLE, Franc, TOPIČ, Marko. One-dimensional semi-coherent optical model for
thin film solar cells with rough interfaces. Informacije MIDEM, Vol. 32 (2002), pp. 6-13.
or
KRČ, Janez, SMOLE, Franc, TOPIČ, Marko. Analysis of light scattering in amorphous Si:H solar
cells by a one-dimensional semi-coherent optical model. Progress in photovoltaics, Vol. 11 (2003),
pp. 15-26.
when publishing papers  dealing with optical matters worked out with our simulator
SunShine  at conferences, in journal papers or in other type of contributions.
We cordially wish you a successful use and exploitaition of SunShine simulator!
Janez Krč
Contents
1 INSTALLATION ................................................................................. 1
1.1
1.2
1.3
1.4
1.5
System Requirements for SunShine v1.2.8....................... 1
Installation of SunShine v1.2.8 optical simulator ........... 1
Installation of USB hardware security key ....................... 2
Running SunShine v1.2.8 optical simulator .......................... 3
UnInstallation SunShine v1.2.8 optical simulator ................ 3
2 DESCRIPTION OF USER'S INTERFACE................................ 4
2.1
2.2
2.3
2.4
2.5
2.6
2.7
Top Command Line (File, Tools, Help)................................. 4
Structure ..................................................................................... 14
Haze Parameters ........................................................................ 17
Angular Distribution Function ................................................ 19
Total Reflectance and Transmittance ..................................... 28
Illumination Spectrum .............................................................. 31
Files ............................................................................................ 32
2.8
Additional Comments/Settings ................................................... 34
2.9 Process Window ........................................................................ 34
2.10 Results ........................................................................................ 35
3 DESCRIPTION OF FILES............................................................... 39
3.1 Input files .................................................................................. 39
3.2 Output files ............................................................................... 47
4 SIMULATION EXAMPLE .............................................................. 54
Appendix 1 (Numerical methods used in Optimo)......................... 63
Appendix 2 (Installation of FTDI drivers) .................................. 66
SunShine v1.2.8 Optical Simulator
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1. INSTALLATION
Contents of SunShine optical simulator Installation pack:
 Installation CD-ROM
 USB hardware security key
 User's manual
Before installation minimum system requirements should be checked.
1.1 System requirements for SunShine v1.2.8
o
o
o
o
o
o
o
o
o
Microsoft Windows XP, Windows 7 (or Vista, 2000)
Decimal separator (Regional Settings) should be "." (not ","!)
Intel Pentium processor (> 1.4 GHz recommended)
32 MB of available RAM (48 MB or more recommended)
Video card with at least 1024x768 pixel resolution and 8-bit/256 colours
CD-ROM drive
USB port
5 MB of available hard-disk space for installation
Adobe Reader 5.0 or higher installed
Two types of installations have to be carried out in the order specified:
1. Installation of SunShine v1.2.8 optical simulator
2. Installation of USB hardware security key
1.2 Installation of SunShine v1.2.8 optical simulator
Note: Do not insert the USB hardware security key before installing this software.
1. Log on your computer as an administrator (or user with administrative rights). See
your operating system Help for how to log as an administrator.
2. It is recommended to close all programs on the computer.
3. Insert Installation CD-ROM into the computer’s CD-ROM drive.
4. InstallShield Wizard (Figure 1) will appear on the screen and guide you through the
installation process. Press Next.
If the installation application does not start automatically: On the Start menu, click
Run, and type: X:setup.exe (where x is the letter of the CD-ROM drive).
5. When the installation is complete, window in Figure 2 will appear. Click Finish.
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Figure 1
Figure 2
1.3 Installation of USB hardware security key
Insert USB hardware security key into a free USB port.
Then FTDI drivers have to be installed by the user. Please refer to original FTDI drivers
installation guides given in Appendix 2 (starting on page 66). Depending on the operation
system on your computer (Win XP, Vista or Win 7) different instructions should be followed.
Please note that drivers from the installation CD should be used (..\\SunShine\Driver_USB).
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1.4 Running SunShine v1.2.8 optical simulator
Note: In order to be able to run simulations, you should have your USB hardware
security key inserted into the computer.
On the Start menu, click Programs > SunShine > SunShine. SunShine interface should
appear on the screen.
1.5 UnInstallation SunShine v1.2.8 optical simulator
The program can be uninstalled using standard uninstallation procedure.
1. Open Control Panel by clicking Start menu > Settings > Control Panel.
2. Double-click on Add or Remove programs to open the wizard.
3. Select SunShine and click the Remove button.
USB hardware security key has separate drivers, which can be uninstalled from Control
Panel.
1. Open Add or Remove programs wizard as described above.
2. Select FTDI FTD2XX USB Drivers and click the Remove button.
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2. DESCRIPTION OF USER'S INTERFACE
The user's interface of the SunShine optical simulator consists of several consoles, which can
be selected by means of menu column on the left side of the main window. On the top of the
interface, a command line is located. In the following sections, all these items will be
described in details.
command line
menu column
structure console
2.1 TOP COMMAND LINE
In the top command line, you can find following menus:
 File
 Tools
 Help.
File
The file menu contains:
 New
 Open input file
 Save input file
 Save input file as
 Print
 Exit
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New
This option is used when creating completely new input file (new structure and new input
parameters).
Open input file
Previously created input files that include information about the simulation structure and all
the corresponding settings of the input parameters are imported into simulator using this
command. The input file has to be in a standard format, which is created by the simulator,
using command ‘Save input file or Save input file as’.
Save input file
You can save the simulation structure and all the corresponding settings (including paths to
the data folders used) in a standard format of simulator input file. In this way, the structure
and all the settings can be imported in the simulator again by using command ‘Open input
file’.
Save input file as
You can save the simulation structure and all the corresponding settings in an input file with a
new name.
Print
Two options are available:
 Print input file: input file with the simulation structure and all the
corresponding settings are printed in text format.
 Print results: The graph created in the Results console, including the main description
of the structure, and comments are printed out. You can also create a pdf file with the
results if there is Acrobat Distiller installed on your computer (pdf printer).
Exit
Exit the simulator program.
Tools
Following option can be found in this menu:
 cR_cT transform
 Optimisation tool
 Calculate LPIF
cR_cT transform
The interface of the transform is given below.
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cR_cT transform calculates haze calibration functions for reflected (cR) or transmitted (cT)
light at a rough interface. The input data are measured haze values as a function of light
wavelength (for details about transformation refer to documentation Scattering parameters).
The transforms creates cR*.cal or cT*.cal files corresponding to one rms roughness (one
substrate in one file).
In the transform window you can select/define:
 cR or cT transform (depending on which transform you want to perform) For haze
values for reflected light cR should be selected whereas for haze corresponding to
transmitted light cT should be used. In case of selecting cT, additional setting for HT
power factor appears. This is a power factor in the equation of scalar scattering theory
that defines the HT values of a rough interface. Options 2, 3 and user defined are
possible. Note that the same value as selected here in this transform should be used
later in the simulations (defined by power factor in console Haze parameters).
 Select the file with (measured) haze data which has to be in a standard format and
*.txt extention. The standard format is as follows: no header, first column
wavelength in micrometers, second column the haze values (for reflected or
transmitted light)
 Define vertical root mean square roughness (in nanometers) of the interface where the
specified haze data were determined. This value is used in transform.
 Define incident layer - file with the nk data of the incident layer (medium) from which
the light approaches the interface should be specified (for details on selection refer to
description of Structure console, section on Layers). For example by measuring the
haze for transmitted light at glass/TCO/air substrate with textured TCO/air interface
(surface), the incident layer of the interface is TCO. In case of haze measurements of
reflected light incident medium is typically air.
 Define layer in transmission - file with the nk data of the layer (medium) in which the
light is entering through the interface (for details on selection refer to description of
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Structure console, section on Layers). For example by measuring the haze for
transmitted light at glass/TCO/air substrate with textured TCO/air interface (surface),
the layer in transmission of the interface is air. In case of haze measurements of
reflected light medium in transmission is typically thin Ag film.
Specify the folder of the nk data - the folder where the files (*.nk) with the complex
refractive indexes of layers are stored.
Specify the name of the cR or cT file - the name of the file where the calculated cR or
cT data as a function of wavelength are stored. The extension of the file should be
*.cal (calibration files for haze parameter)
Specify the folder of the cR or cT file - the folder where the created cR and cT files
are stored.
Run button
The transform is lunched by clicking on this button.
Optimisation tool
The interface of the optimisation tool OPTIMO is shown below:
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By means of the transform optimal thickness, roughness, refractive index and/or extinction
coefficient of selected layer and interfaces can be searched according to the selected criteria
for the photocurrent Jsc<photo> of the specified layer(s). Optimisation on Jsc<photo> is
important because in the active layers (PV active) the Jph<photo> presents the potential
photocurrent which can be gained (can be used for maximising the photocurrent of the cell),
whereas in the non-active layers the corresponding Jsc<photo> represents the optical losses
expressed in the photocurrent units (can be used for minimising the optical losses in the cell).
In the optimisation process the structure which is currently defined in the SunShine
consoles (considering all the input parameters set) is optimised.
Optimisation process and the input/output files involved are schematically shown in the figure
below.
variation of the input
parameters
(SSIn.dat)
Optimisation tool
Optimal input
parameters
(*_optimo.out)
SunShine
Jsc<photo>
(*_Sum.jsc)
results of each
iteration
(*_optimo_iter.out)
SunShine simulator is run by the optimisation tool automatically. The values of the optimising
input parameters for the next iteration are defined by the optimisation tool.
Basic results (optimal parameter(s)) of the optimisation are displayerd in the Results section
of the tool and stored in the *_optimo.out file. The values of the optimisation parameter(s)
and the corresponding Jsc<photo> of all iterations performed are stored in the
*_optimo_iter.out file in the selected output folder.
In the following the interface of the optimisation tool is explained:
OPTIMISATION OF Jsc<photo>
Optimise the JSC<photo> of selected layers
Select the sequence number(s) corresponding to the layer(s) of which the Jsc<photo> is to be
optimised. The layer number can be found in the SunShine Structure console (in front of the
layer name). If number “0” is entered into the box, optimisation on Jsc<photo> optical losses
corresponding to the reflected light from the structure (R) is optimised. If N+1 layer is
specified the optimisation on the transmitted light (if any) is carried out.
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More layers than one can be entered (use comma delimiter). In this case the Jsc<photo> of the
selected layers are summed up and their sum is considered as a new Jsc<photo> value for
optimisation. The only exception ocurrs if the third optimisation criteria (“Find minimal
difference...” see further) is selected. In this case the difference between first and the second
specified layer is taken as a Jsc<photo> valze for optimisation.
Optimisation criteria
The following three options are possible to be chosen:
 Find minimal Jsc<photo> of the selected layer(s)
 Find maximal Jsc<photo> of the selected layer(s)
 Find minimal difference in Jsc<photo> between two specified layers
The first option can be used for minimisation of the optical losses (Jsc>photo> losses) in the
selected (non-active) layer(s).
The second option is used to gain Jsc<photo> in the selected (active) layer(s) – in this way the
short circuit current of the cell can be improved.
The third option is used to find the optimal parameters for the minimal difference in the
Jsc<photo> of two layers  first two specified – can be utilised to perform the current
matching in a tandem cells.
OPTIMISATION PARAMETERS
Four optimisation parameters can be selected, each one separately or up to 4 simultaneously
(more dimensional optimisation):
 THICKNESS of the selected layer
 ROUGHNESS of the selected interface(s)
 REFRACTIVE INDEX of the selected layer
 EXTINCTION COEFFICIENT of the selected layer
THICKNESS of the selected layer
The optimal thickness of the selected layer is searched (only one layer at once), according to
the optimisation criteria selected. To enable this option check the corresponding checkbox.
Further on, enter the selected layer number in the box below. There are three options to
determine the interval of the thickness variation (within this interval the solution is searched):
 absolute from (a) nm to (b) nm
 relative to initial thickness from –(a) to +(b) nm
 relative to the initial thickness from –(a) % to +(b) %
Select the option and enter the number for (a) and (b) into the corresponding boxes.
ROUGHNESS of selected interface(s)
The optimal vertical rms roughness(es) of selected interface(s) are searched. More than one
interface can be selected for roughness optimisation in the corresponding box (delimiter
comma). This option is offered because by changing the roughness of the substrate, the
roughnesses of all deposited layers on the substrate are affected. If more interfaces is selected,
their roughness is changed equally in the optimisation process (following the selected rule for
changing). The optimisation is carried out on the set of interface roughnesses and not for each
particular interface separately!
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REFRACTIVE INDEX of selected layer
The optimal value of the refractive index (n) of the selected layer is searched. the interval of
the relative change of the refractive index can be defined. This interval is considered equally
for all n values corresponding all wavelengths used. Thus, n values in entire wavelength
region are changed following the same rule. The optimisation is not applied for each
wavelength separately! As a result, the optimisation tool returns the FACTOR which defines
the optimal n values as n_optimal = n_initial*FACTOR (should be calculated by the user!).
EXTINCTION COEFFICIENT (k) of selected layer
The optimal value of the extinction coefficient of the selected layer is searched, in the same
way as the refractive index in the previous case. As a result the FACTOR defining the optimal
k is deterimined, thus, the optimal k can be calculated as k_optimal = k_initial*FACTOR
NUMERICAL METHODS
The method defining the way of changing the selected input optimisation parameters
(thickness, roughness, n, k), according to the values of Jsc<photo> from previous iterations.
Following numerical methods can be selected in the optimisation tool:





Simulated annealing with high probability (slower method, high probability of finding
a global extreme)
Simulated annealing with normal probability
Simulated annealing with low probability (faster method, high probability of finding a
local extreme)
Simplex (finds local extreme)
Constant steps
A detailed description of the methods can be find in Appendix 1 of this manual.
Stop the optimisation if Jsc<photo> of the last two itteration is smaller than
%.
Define the criteria for finishing the optimisation process. Besides this criteria the optimisation
is stopped also if the absolute difference in Jsc<photo> is greater or equal 0.001 mA/cm2 or if
the number of iterations exceeds 2000.
RUN OPTIMISATION button
Run/Terminate the optimisation process.
Current Iteration number
Indicates how many times the SunShine simulator has been run (finished with calculation) so
far in this optimisation process. Maximal number of iterations is 2000.
RESULTS
Basic results (optimised input parameters) are displayed. Complete optimisation results you
can find in the *_optimo_iter.out and *_optimo.out files (see description of the files in the
section devoted to the Output files).
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NOTES:
For structures with many layers and rough interfaces the SunShine simulator may need
several minutes (up to 10 min) to calculate the results. In the optimisation process of
such structures it has to be considered that the executing time of the optimisation may
be therefore relative long (No. Iter x Time_of_one_SunShine_run.)
Running the optimisation tool the SunShine hardware security key has to be inserted
into the USB port to enable the iterative execution of the SunShine (no special message
in the optimisation tool is displayed if the key is not inserted!)
During optimisation process, the SunShine simulator should not be started manually!
For any error occurred during optimisation (SunShine error) please refer to the
SSMessage.dat file!
Calculate LPIF
The interface of the transform is shown below:
The transform calculates the Light Path Improvement Factor – LPIF in a layer in two different
optical systems. The factor defines how much the optical path of the light crossing the layer is
improved in the “improved” optical system (structure) according to the “reference” structure.
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Example:
Reference structure:
air
i-a-Si:H d = 100 nm
i-a-Si:H infinite (to avoid back reflection)
Improved structure:
air
i-a-Si:H d = 200 nm
i-a-Si:H infinite (to avoid back reflection)
Result:
LPIF = 200 nm/100 nm = 2.0
In general LPIF is wavelength dependent.
The definition of the LPIF in the transform is as follows:
LPIF 
d eff
dinit
I (d )
I (0)

I (d )
ln init
I init (0)
ln
deff – effective (equivalent) thickness of the layer in the improved structure (caused not
necessarily due to the actual thickness prolongation but sue to improved improved light
trapping, scattering, ...)
dinit – actual thickness of the layer in the reference structure
I(d) – total light intensity (including forward and backward going waves and rays +
interferences) at the end of the layer
I(0) – total light intensity (including forward and backward going waves and rays +
interferences) at the entrance of the layer
Iinit(d) and Iinit(0) – total light intensities in the layer in the reference structure
The natural logarithm functions originates from the natural logarithmic dependency d(I) (or in
other words, I(d) is following the exponential relation to d; I(d) = I(0) exp (-d)), where  is
the absorption coefficient of the layer (at a given wavelength).
In the following the interface of the Calculate LPIF tool is exolained.
Select the “*_ratio.jph” file of the reference structure
The “*_ratio.jph” is one of the output files of the SunShine v1.2.8 simulator. As described in
the section devoted to the Output files, the file consists of the ratio values I(d)/I(0) (for each
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simulated wavelength), required for the LPIF calculation. The “*_ratio.jph” file of the
reference structure should be selected using Browse button.
Select the “*_ratio.jph” file of the improved structure.
The “*_ratio.jph” file of the improved structure should be selected using Browse button.
SELECT THE LAYER (column)
In the table below the user should select the column that corresponds to the layer in which
LPIF will be calculated! The column should be selected for the reference as well as for the
improved structure (typically, the same layer should be selected in both cases). If no column
is selected by the user the first layer is considered for the LPIF calculation.
Specify the name of the LPIF output file
The name of the output file (without extension) where the LPIF values as a function of the
wavelength will be stored should be entered. The tool adds the extension *.lif to the output
file automatically. It is recommended to give the *lif file a name, which links the names of
the reference and the improved structure (for later recognising)
Specify the folder of the LPIF output file
Define the folder in which the *.lif file will be stored.
RUN button
Execute the calculation and create the *.lif output file
Results
LPIF values as a function of the wavelength are displayed in the table. The displayed values
are stored also in the above specoified *lif file. If NAN are involved in the results, the
calculation of the LPIF vas not possible with the given I(d) and I(0) values (in most cases the
reason is too high absorption in the layer for shorter wavelengths usually).
Help (located in the basic command line of the SunShine simulator)
Help menu contains:
 User manual
 About
User manual
A pdf file with this user's manual is opened if Acrobat Reader program is installed on your
computer.
About
Basic information about the version of the SunShine optical simulator is given.
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Menu column
The menu column is located on the most left side of the interface window. It contains
following items:









STRUCTURE
HAZE PARAMETERS
ANGULAR DISTRIBUTION FUNCTIONS
TOTAL REFLECTANCE AND TRANSMITTANCE
ILLUMINATION SPECTRUM
FILES
ADDITIONAL SETTINGS / COMMENTS
PROCESS WINDOW
RESULTS
By selecting specific option, corresponding console window is opened. Each console is
discussed in detail in the following sections (2.1 - 2.8).
The outlook of each of the console can be viewed in section 4 where the settings for a
simulation example are shown.
Show Advanced Settings/Hide Advanced Settings button
The corresponding button appears if following options are selected in the menu column:
Structure, Haze parameters, Angular Distribution Function, Total Reflectance and
Transmittance, Illumination Spectrum and Files. It enables to see/hide and include or modify
the specific advanced settings, given in the selected console.
Run/Terminate button
This is the button for running (terminating) the simulation. Before running the simulation the
user should always check, if all input parameters in the consoles Structure, Haze parameters,
Angular Distribution Function, Total Reflectance and Transmittance, Illumination Spectrum
and Files are set properly.
2.2 STRUCTURE
In this console simulated (multilayer thin-film) structure is defined.
Basic settings
Following parameters can be determined:
 PV active
 Layers
 Thickness
 No of Segm.
 Roughness rms
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PV active
By activating the check box, corresponding to a specific layer, the layer is considered as a
photovoltaic active. This means that light absorption therein causes generation of electronhole pairs (photogenerated charge carriers, Gl). The phenomenon is typical for semiconductor
materials (e.g. p, i, n a-Si layers). For the layers with selected PV active check box, generated
charge carriers profiles is calculated and written in *.Gl output file.
Layers
A layer in the multilayer structure is represented by the name of the file, where corresponding
complex refractive indexes (N = n -jk) as a function of wavelength are specified:
(<workdir>\nk\Layer_name.nk file). The name of the layer that appears in the corresponding
text box does not include the file extension .nk.
Restrictions for the name of a layer
The name can include letters, numbers and "_" character (e.g. i_aSiH, TCO1). It should not
contain spaces or strange characters (e.g. : , ; etc.). The maximum number of characters in the
name is limited to 50.
Selecting a layer
By clicking the down arrow on the right side of the layer box, available layers that are listed
in <workdir>\\List\layers.dat are shown. You can select one of these layers or write the name
of another layer directly in the box. In this case be sure that there exists the_layer_name.nk
file with corresponding complex refractive indexes of the layer in <workdir>\nk folder.
Adding and Removing layers
First and last row of the layer boxes correspond to incident and outgoing media, respectively.
Default incident and outgoing media is air.
You can add or remove layers using following two options:
 Adding or removing one or several layers on the bottom (back) side of the existing
structure can be done by clicking ADD or REMOVE button on top right side of the
window.
 Adding or removing a layer inside the structure can be done by clicking right mouse
button on the layer index (number located on the left side of the layer name) and select
Add layer above or Delete layer option.
Maximum number of layers
Maximum number of layers is limited to 40.
Thickness
In the corresponding boxes you can specifies the layers' thickness in nanometers.
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No. of Segm.
The number of segments of equal length inside the layer of a given thickness is determined.
With this parameter the numerical calculation grid (calculation points for position, axix x) is
determined in the layer (see next example). In these points the simulation results, which
depend on position, x, in the structure, are given in the output files (*.Gl, *jph).
An example of a layer with No. of Segm. = 3 is shown in the following figure:
layer
d

1. segm. 2. segm. 3. segm.



calculation points
The number defining No. of. Segm. should be an integer greater or equal to 1. The total
number of segments (sum of all layers) should not exceed 2500.
Roughness rms
The vertical root-mean-square roughness, rms (or r), of specific interface is defined. For
definition and physical background of rms refer to the documentation on Optical model and
Scattering parameters.
Advanced Settings
By clicking the button Show Advanced Settings, the conditions for the incoherent analysis of
specific (thick) layers can be viewed and set. The SunShine version 1.2 enables up to three
(thick) layers to be treated incoherently. The detection (selection) of the incoherent layers is
automatic, considering the following thickness conditions (thicknesses are denoted with d):
Fully coherent layers:
d > dincoh;
dincoh = dincoh_init * I_factor
dincoh_init =  2/(2**n)

 ... light wavelength in the air (nm)
 ... spectral width of the monocromatic
n ...
illumination in meas. setup (set to 4 nm)
refractive index of the layer
Fully coherent layers:
d < dcoh;
dcoh = dincoh / C_factor
In/coherent layers
dcoh ≤ d ≤ dincoh
In/coherency level is calculated as a linear
function of d
At an interface, I_factor and C_factor can be set by the user (default values are 1). The thick
layers that are to be treated incoherently can be located at any position in the structure. If
there are more than three thick layers exciding the condition d < dcoh, only the three optically
thickest layers that exceeds the condition are treated incoherently, the rest are analysed as
fully coherent layers (irrespective of their thickness).
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2.3 HAZE PARAMETERS
Haze parameters describe how much of light is scattered at a rough interface in the structure.
Basic settings
Haze parameters can be defined in two ways:
 Select power factor for calculation of haze parameter for transmitted light (HT)
 Use calibration functions (cR and cT)
 Use haze input data (HR, HT)
Select power factor for calculation of haze parameter for transmitted light (HT)
Power factor in the equation of scalar scattering theory, defining the haze parameter for
transmitted light (HT), is defined here (for more information on the meaning of this factor
please refer to the documentation on Scattering parameters). Options 2, 3 or user defined can
be selected.
Use calibration functions (cR and cT)
By selecting this option you can specify the calibration function for haze parameter for
reflected light, cR (left text box below), and for haze parameter for transmitted light, cT (right
box below), separately.
The calibration functions are needed in the modified equations of scalar scattering theory that
are used to calculate haze parameters, HR and HT, at an internal interfaces (for details and
physical background refer to documentation on Scattering parameters).
The calibration functions, cR and cT, are represented by the name of the file where
corresponding cR or cT values are specified (<workdir>\cT_cR\CR_name.cal file). The name
of the calibration function that appears in the box does not include the file extension .cal.
Restrictions for the name of a calibration function
The name can include letters, numbers and "_" character (e.g. cT_05, cR_1). It should not
contain spaces or strange characters (e.g. : , ; etc.). The maximum number of characters in the
name is limited to 50.
Selecting a calibration function
By clicking the down arrow on the right side of the text box, available calibration functions
cR and cT that are listed in <workdir>\\List\cR.dat and <workdir>\\List\cT.dat, respectively,
are shown. You can select one of these calibration function or write the name of another
calibration function directly in the box. In this case be sure that there exists the_name.cal file
with corresponding calibration functions in <workdir>\cT_cR folder.
Use haze input data (HR, HT)
By selecting this option you can define the haze parameters of rough interfaces for reflected
light, HR (left box below), and transmitted light, HT (right box below), separately.
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The haze data, HR or HT, are represented by the name of the file where corresponding HR or
HT values are specified (<workdir>\HT_HR\HT_name.tis file). The name of the haze data
that appears in the box does not include the file extension .tis.
The HR and HT values that are given in *.tis files correspond to the interface between two
specific layers that are determined on the top of the *.tis file. In order to apply these haze data
to internal interfaces in the structure, corresponding cR and cT functions are determined in the
model internally.
Restrictions for the name of a calibration function
The name can include letters, numbers and "_" character (e.g. HT_01_TCO_air,
HR_01_air_Ag). It should not contain spaces or strange characters (e.g. : , ; / etc.). The
maximum number of characters in the name is limited to 50.
Selecting haze input data
By clicking the down arrow on the right side of the text box, available haze data HR and HT
that are listed in <workdir>\\List\HR.dat and <workdir>\\List\HT.dat, respectively, are
shown. You can select one of these haze data or write the name of another haze data directly
in the box. In this case be sure that there exists the_name.tis file with corresponding haze
values in <workdir>\HT_HR folder.
Advanced Settings
By clicking the button Show Advanced settings, following two options are possible to be
included:


Use other haze parameters for specified interfaces
At specified interfaces coherent specular light, coming from the front (top) side of
the structure is scattered in transmission only
Use other haze parameters for specified interfaces
By including this setting you can apply other Calibration functions or Haze input data to
specified interfaces.
You can specify one or more interfaces in the box by giving their index number. The index
number is starting from zero for front surface (incident_medium/1st_layer interface) and
extension at number of all layers for back surface (last_layer/outgoing_medium interface).
By specifying more than one interface in the box, the corresponding index numbers should be
separated by commas ",". In case that interface index exceeds the number of layers in the
structure, it is not considered in the simulation.
The selection of Calibration functions and Haze data is performed in the same way than in
basic settings (see Basic Settings of Haze parameters)
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At specified interfaces coherent specular light, coming from the front (top) side of the
structure is scattered in transmission only
By including this setting you can exclude light scattering of reflected light in case of coherent
incident light coming to the rough interface from the front (top) side of the structure. Situation
is illustrated in the following figure.
The interfaces can be specified in the same way as in the case of the previous advanced
setting.
2.4 ANGULAR DISTRIBUTION FUNCTIONS
Angular distribution functions describe angular (directional) dependency of scattered light (in
which directions light is scattered at rough interfaces).
Angular distribution functions for scattered (diffused) light at rough interfaces are defined in
this console.
Basic Settings
Following basic settings are available:
 No of equivalent angles per 90 degrees
 Settings for ADF1
 Settings for ADF2
No of equivalent angles per 90 degrees
Definition of angular discrete grid for ADFs. The value determines the number of discrete
directions in which diffused beams are propagated in the simulator. The directions refer to the
angles between 0 degree (perpendicular direction to the interfaces) and 90 degrees.
For example, setting the number of equivalent angles per 90 degrees to 3, the equivalent
angular step is 90 degrees / 3 = 30 degrees, as shown in the following figure.
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By assuming the spherical symmetry, the description for this angular range is valid also in the
range from 90 to 0 degrees.
The default and advised value for No of equivalent angles per 90 degrees is 45.
In the following subsections the settings for ADF1 and ADF2 are described.
ADF1 corresponds to the case of perpendicular incidence of coherent specular light, whereas
ADF2 corresponds to the incidence of incoherent scattered (diffused) light beam at a rough
interface.
Settings for ADF1
Two options are possible to define ADF1 of the rough interfaces inside the structure:


Use internally defined ADF1
Use externally defined ADF1
Use internally defined ADF1
Internally defined ADF1s are pre-determined inside the model. For some internal ADF1s
external parameters that can be defined by the user.
Internal ADF1 is defined for reflected (ADF1R) and transmitted light (ADF1T) scattered at
rough interfaces. Selection in the console can be made by clicking the down arrow on the
right side of the boxes for specifying ADF1R (upper box) and ADF1T (bottom box).
In both cases one can choose between following 9 basic predefined ADF1s:









Specular direction (incoherent)
Lambertian cos^n
Lambertian cos^n 3D
Ellipsis
Ellipsis 3D
Equal in all directions (half circular)
Equal in all directions (half circular) 3D
Linear
Linear 3D
In case that any other specific ADF1 is activated (check the list of available internal ADF1s
by clicking the down arrow at the right side of the ADF selection box), please contact authors
([email protected]) for additional information.
All options except the first appear with and without 3D indexation. The 3D indexation means
that the ADF transformation from 3 dimensions to 1 dimension (1D, 3D transformation) is
performed on the original ADF. This transformation enables that information on scattering in
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3D is considered in 1D model. The transformation is simply represented by given
multiplication factor in the following equation:
ADF3 D ,1D  ADF  (cos   cos( 

)) ,
2
where  is scattering angle and ADF is angular distribution that refers to the ARS
measurements performed in a plane. Detailed explanation of this transformation exceeds the
scope of this manual. For further information on this topic refer to the documentation on
Scattering parameters.
In the following subsections the nine ADF1 options are described and represented in
Cartesian and Polar plot as a function of scattering angle in the range from  90 to 90 degrees.
They refer to both, ADF1R and ADF1T.
Specular direction (incoherent)
In this case all the diffused light beams are propagating in specular direction (as in case they
were not scattered). Thus, the direction of scattered light beams remains perpendicular, only
the nature of light is changed from coherent (incident specular beam) to incoherent.
Lambertian cos^n
Lambertian cos^n 3D
ADF is determined by Lambertian (cosine) function of scattering angle in this case. The
factor n in the denotation represents the power of cosine function (square, qubic, ...) and can
be specified in the additional box that appear in case of choosing Lambertian ADF1.
The ADF functions with and without the mentioned 1D,3D transformation are plotted in
Cartesian and Polar plot (for n = 1) in the following two figures.
90
1.0
120
1.0
ADF
Angular distribution function, ADF
60
0.8
0.6
0.8
150
30
0.4
0.2
0.6
ADF1D,3D
180
0.0
0
0.4
0.2
210
ADF
ADF1D,3D
0.0
-90
-60
-30
0
30
60
90
240
Scattering angle,  (degree)
300
270
Lambertian ADF with power 1 results in a circle in the polar plot
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Ellipsis
Ellipsis 3D
ADF is represented by geometrical ellipsis. The ADF functions with and without 1D,3D
transformation are plotted in Cartesian and Polar plot in the following figures.
90
1.0
120
1.0
ADF1D,3D
ADF
Angular distribution function, ADF
60
0.8
0.6
0.8
150
30
0.4
0.2
0.6
180
b
a
0.0
0
ADF
0.4
0.2
ADF1D,3D
210
330
0.0
-90
-60
-30
0
30
60
90
Scattering angle,  (degree)
240
300
270
The radius ratio b:a defines the broadness of the ellipsis and thus of the ADF. Larger the b:a
ratio is, more light is scattered into larger scattering angles (away from specular direction).
The b:a ratio can be specified in the box that appears additionally if Ellipsis (3D) ADF is
selected.
Equal in all directions (half circular)
Equal in all directions (half circular) 3D
ADF  1 for all scattering angles in this case. The ADF functions with and without 1D,3D
transformation are plotted in Cartesian and Polar plot in the following two figures.
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90
1.0
120
60
1.0
0.8
Angular distribution function, ADF
ADF
0.6
150
0.8
30
0.4
0.2
0.6
ADF
180
0.4
0.0
0
ADF1D,3D
ADF1D,3D
0.2
210
330
0.0
-90
-60
-30
0
30
60
90
240
Scattering angle,  (degree)
300
270
Linear
Linear 3D
ADF is represented by linear function of scattering angle. The ADF with and without 1D,3D
transformation are plotted in Cartesian and Polar plot in the following two figures.
90
1.0
120
Angular distribution function, ADF
1.0
60
0.8
ADF
0.6
0.8
150
30
0.4
0.2
0.6
180
0.0
ADF
0
0.4
0.2
ADF1D,3D
210
330
ADF1D,3D
0.0
-90
-60
-30
0
30
60
90
Scattering angle,  (degree)
240
300
270
Linear ADF results in triangular shape in Cartesian plot.
Use externally defined ADF1
Externally defined ADF1Rs and ADF1Ts are determined in external files located in
<WORKDIR>\ADF_external and can be created by the user.
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The ADF1Rs and ADF1Ts are represented by the name of the file where corresponding
ADF1R and ADF1T values are specified (<workdir>\ADF_external\ADF1_name.ars file).
The name of the ADF1R and ADF1T that appears in the box does not include the file
extension .ars.
Restrictions for the name of external ADF1R and ADF1T
The name can include letters, numbers and "_" character (e.g. ADF1R_TCO1). It should not
contain spaces or strange characters (e.g. : , ; / etc.). The maximum number of characters in
the name is limited to 50.
Selecting external ADF1R and ADF1T
By clicking the down arrow on the right side of the text box, available ADF1R and ADF1T
that are listed in <workdir>\\List\ADF1ext.dat are shown. You can select one of these ADF1
data or write the name of another external ADF1 directly in the box. In this case be sure that
there exists the_name.ars file with corresponding ADF1R or ADF1T values in
<workdir>\ADF_external folder.
Settings for ADF2
As in case of ADF1, also here two options are possible to define ADF2:
 Use internally defined ADF2
 Use externally defined ADF2
Use internally defined ADF2
Internally defined ADF2s are pre-determined inside the model. Some of the internal ADF2s
have additional parameters that can be set by the user.
ADF2 can be defined for reflected (ADF2R) and transmitted light (ADF2T) scattered at rough
interfaces. Selection can be made by clicking the down arrow on the right side of the boxes
for specifying ADF2R (upper box) and ADF2T (bottom box).
In both cases one can choose between following 13 pre-defined ADF2s:
 Specular direction (incoherent)
 Lambertian cos^n
 Lambertian cos^n 3D
 Ellipsis
 Ellipsis 3D
 Ellipsis - dependent on incident angle
 Ellipsis - dependent on incident angle 3D
 Equal in all directions
 Equal in all directions 3D
 Linear
 Linear 3D
 Linear - dependent on incident angle
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Linear - dependent on incident angle 3D
In case that any other specific ADF2 is activated (check the list of available internal ADF2s
by clicking the down arrow at the right side of the ADF selection box), please contact authors
([email protected]) for additional information.
All options for selection of ADF1 are included also here. Since ADF2 in general depends on
incident angle of the illumination beam, 4 new options are added to the internal ADF2
selection (denoted with dependent on incident angle). For these options dependency on
incident angle is included. In this case also an additional ADF transformation (besides ADF3D,
1D) related to spherical symmetry of incident illumination (resulting in a cone instead of one
beam illumination) is taken into account in the simulator. For the information on this
transformation refer to the documentation on Scattering parameters.
Specular direction (incoherent)
The same as in case of ADF1 (refer to description of this option in ADF1 section).
Lambertian cos^n,
Lambertian cos^n 3D
The same as in case of ADF1 (refer to description of this option in ADF1 section).
Ellipsis
Ellipsis 3D
The same as in case of ADF1 (refer to description of this option in ADF1 section).
Ellipsis - dependent on incident angle
Ellipsis - dependent on incident angle 3D
An example of Ellipsis ADF, which includes dependency of incident angle, is shown in Polar
plot in the following figure.
90
1.0
120
60
outgoing
specular beam
0.8
a
0.6
150
30
b
0.4
ADF
0.2
180
0.0
0
210
330
240
300
270
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The ellipsis is rotated according to the angle of outgoing specular beam, which is related to
the incident angle by Snell's law. In the figure the 1D, 3D transformation and the
transformation due to spherical symmetry (cone illumination) is not included.
Equal in all directions (half circular)
Equal in all directions (half circular) 3D
The same as in case of ADF1 (refer to description of this option in ADF1 section).
Linear
Linear 3D
The same as in case of ADF1 (refer to description of this option in ADF1 section).
Linear - dependent on incident angle
Linear - dependent on incident angle 3D
In case of dependency on incident angle the peak of triangle corresponding to the Linear ADF
is shifted according to the angle of outgoing specular beam. The angle of outgoing specular
beam is related to the incident angle by Snell's law. In the following figure an example of
Linear ADF2 for non-perpendicular incident angle is shown in Cartesian plot. The 1D, 3D
transformation is not included. However, the approximation used in the simulator to include
spherical symmetry (cone illumination instead of one beam illumination) is shown in the
figure. In case of a cone illumination, the triangular shape of linear ADF is transformed into
trapezoidal shape.
Angular distribution function, ADF
1.0
ADFcone ill.
0.8
ADF
0.6
1
0.4
0.2
0.0
-90
-60
-30
0
30
60
90
Scattering angle,  (degree)
Use externally defined ADF2
By selecting this option you can select ADF2R and ADF2T of rough interfaces defined in
external files located in <WORKDIR>\ADF_external and that can be created by user.
The ADF2R and ADF2T are represented by the name of the file where corresponding ADF2R
and ADF2T values are specified: <workdir>\ADF_external\ADF2_name.ars file. The name of
the ADF2R and ADF2T that appears in the box does not include the file extension .ars.
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Restrictions for the name of external ADF2R and ADF2T
The name can include letters, numbers and "_" character (e.g. ADF2R_TCO1). It should not
contain spaces or strange characters (e.g. : , ; / etc.). The maximum number of characters in
the name is limited to 50.
Selecting external ADF2R and ADF2T
By clicking the down arrow on the right side of the text box, available ADF2R and ADF2T
that are listed in <workdir>\\List\ADF2ext.dat are shown. You can select one of these ADF2
data or write the name of another external ADF2 directly in the box. In this case be sure that
there exists the_name.ars file with corresponding ADF2R or ADF2T values in
<workdir>\ADF_external folder.
Advanced Settings
By clicking the button Show Advanced settings, following option is possible to be included:
Use other ADFs for specified interfaces groups
By including this setting you can apply other (different) ADFs to specified group of
interfaces. In this version it is possible to include up to 15 interface groups with different
ADF settings. For each interface group you can specify one or more interfaces to which the
selected ADFs are applied to (see below). It has to be mentioned that the ADFs defined in the
basic settings apply to all interfaces except the ones defined in the advanced settings (if
switched on) – for these interfaces the basic ADF settings are overwritten with the new ones
defined here. If one or more interfaces are (by mistake) present in different ADF interface
groups the settings corresponding to a higher ADF group number are considered. Details are
explained in the picture below.
switch on/off other ADF settings
add new group
at the end
move to a higher (up) or lower (down)
interface group
delete the selected group
(and shift all succeeding for
1 number lower)
specify the interfaces to which
the ADFs selected below will be
applied to.
In the lower part of the window you can select the ADFs (internal or external) as in the case
of the basic ADF settings above (see section on the basic ADF settings).
As mentioned, one or more interfaces can be specified in the group by giving their index
(serial) number. The index number is starting from zero for front surface
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(incident_medium/1st_layer interface) and ending at number of all layers for back surface
(last_layer/outgoing_medium interface).
By specifying more than one interface in the box, the corresponding index numbers should be
separated by commas ",". In case that the interface index exceeds the number of layers
(interfaces) in the structure it is not considered in the simulation.
Useful hint: if you want to apply different ADF settings to each interface in the structure it
can be done in the following way: in the basic ADF settings set the ADFs which will be
applied to the 0th interface. In the advanced settings create as many ADF interface groups as
the total number of the interfaces is (starting with the 1st). In each interface group define only
one interface, the most convenient is that the number of the ADF interface group corresponds
to the number of the interface. Please note that the defined ADFs are still common for
illuminations from both sides of the interface.
2.5 TOTAL REFLECTANCE AND TRANSMITTANCE
Total (specular+diffused) reflectance and (specular+diffused) transmittance at interfaces can
be corrected in this console.
Basic Settings
Include following calibration factors to decrease total reflectance at specified interfaces
The total reflectance of interfaces (rough or flat) can be decreased by factor c12 for the light
(both, specular and diffused component) approaching the interface from the front (top) side of
the structure. For the light approaching the interface from the back side, the total reflectance
at the interface can be decreased by factor c12. Decreased total reflectances for the light from
front side, R12_new, and for the light from back side, R21_new, are calculated as
R12_new = c12 * R12 and R21_new = c21 * R21.
Factors c12 and c21 are limited to 0 ≤ c12 ≤ 1 and 0 ≤ c21 ≤ 1, with a default value of 1. In
case of the default value total reflectances are not affected. They are mainly used to decrease
total reflectance of rough interface (e.g. due to index grading effect etc.). The values of the
factors can be determined based on empirical observations or by means of a theory (e.g.
Effective Medium Theory if applicable to the roughness morphology) outside of the
simulator.
The values specified for c12 and c21 can also be directly used as total reflectances from the
front and back side of the interface. In this case the option "Use specified values c12 and c21
as total reflectance directly" should be selected.
You can specify one or more interfaces in the box, to apply c12 and c21, by giving their index
number. The index number is starting from zero for front surface (incident_medium/1st_layer
interface) and ending at number of all layers for back surface (last_layer/outgoing_medium
interface).
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By specifying more than one interface in the box, the corresponding index numbers should be
separated by commas ",". In case that interface index exceeds the number of layers in the
structure it is not considered in the simulation.
The option "Include following calibration factors to decrease total reflectance at specified
interfaces" can be extended with additional calibration factors (function) - see Advanced
settings in the next paragraph.
Advanced Settings
By clicking the button Show Advanced settings following options are possible to be included:




If option Include following calibration factors to decrease total reflectance at
specified interfaces was selected there appear two additional columns on the top
right to set new c12 and c21 factors at specified interfaces.
Include following functions to decrease total reflectance at specified interfaces
Include following calibration factor to decrease total reflectance of entire
structure and increase the light intensity entering the structure
Include following calibration factor to increase total reflectance from the back
side for scattered light beams at specified interfaces
Include following calibration factors to decrease total reflectance at specified interfaces
In the two new columns additional c12 and c21 factors can be set for corresponding (newly
specified) interfaces. If two or three c12 (c21) are defined for the same interface, their
multiplication is used (if they appear as multiplying factors). In case there are more then one
c12 (c21) defined as the value of total reflectance of an interface (selected option "Use
specified values c12 and c21 as total reflectance directly") the most right value (column) is
taken into account, the rest c12 (c21) specified as values of total reflectance are ignored (but
only if they are specified as the values of total reflectance, in case they present the
multiplication factors they are still taken into account).
Include following calibration functions to decrease total reflectance at specified
interfaces
Besides constant c12 and c21 reflectance calibration factors mentioned above, external
wavelength-dependent functions c12(wavelength) and c21(wavelength) can be used to correct
or set the total reflectance at specified interfaces (two sets). Specific functions should be
defined in separate files (*.brc) in <workdir>\CT_CR folder (see description of *.brc files in
section 3.1 with description of input files). The names of the existing files (without extension)
can be selected by clicking the down arrow on the right side of the text box or can be entered
directly by typing. The list of existing *.brc files is stored in <workdir>\List\ReflCal.dat and
can be managed by user.
This kind of calibration with the function can be used to calibrate the reflectance of e.g. back
contact (back reflector - BR) in the solar cells. Option "Use specified functions c12 and c21 as
total reflectance directly" can be applied by checking the corresponding checkbox..
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Include following calibration factor to decrease total reflectance of entire structure and
increase the light intensity entering the structure
By including this setting total reflectance of entire structure, R_entire, is decreased on basis of
the calibration factor c12_entire, as specified by the equation given in the console. Thus, the
intensity of light that enters the structure, I_enter, can be increased, as defined by the
corresponding equation given in the console.
The c12_entire factor is limited to 0 ≤ c12_entire ≤ 1 with a default value of 1. In case of the
default value the total reflectance and the entering intensity of light are not affected.
This option was found to be useful by simulations of HIT type of solar cells.
Include following calibration factor to increase total reflectance from the back side for
scattered light beams at specified interfaces
By including this setting total reflectance for scattered (diffused) light beams at specified
interfaces is decreased by the factor c21_scat, if the beams are approaching to the interface
from the back side of the structure. Increased total reflectance, R21_scat is defined as
R_21_new = c21_scat * R_21.
The situation is illustrated in the following figure:
front
side
back
side
scattered (diffused)
beam
increased
reflectance
The c21_scat factor is limited to c21 scat ≥ 1. In case that R21 becomes > 1 due to
multiplication with c21_scat, it is set to 1 in the simulator automatically.
By means of c21_scat factor the effects of enhanced light trapping in the structure can be
analysed (in a simplified way).
The interfaces which c21_scatt factor is applied to, can be specified in the corresponding box
in the same way as described for the basic settings.
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2.6 ILLUMINATION SPECTRUM
The incident illumination is defined in this console.
Basic Setting
Illumination spectrum
In the text box you can specify the illumination spectrum (light), which is applied to the
structure from the incident medium. The spectrum is represented by the name of the file
where corresponding light intensities as a function of discrete wavelength of the spectrum are
specified (<workdir>\Spectrum\Spectrum_name.spk file). The name of the spectrum that
appears in the box does not include the file extension .spk.
Restrictions for the name of a spectrum
The name can include letters, numbers and "_" character (e.g. cT_05, cR_1). It should not
contain spaces or strange characters (e.g. : , ; etc.). The maximum number of characters in the
name is limited to 50.
Selecting a spectrum
By clicking the down arrow on the right side of the text box, available spectrums that are
listed in <workdir>\\List\Spectrum.dat are shown. You can select one of these spectrums or
write the name of another spectrum directly in the box. In this case be sure that there exists
the_name.spk file with corresponding spectrum in <workdir>\Spectrum folder.
NOTE: The discrete wavelengths specified in the spectrum file determine the discrete
wavelengths in which the simulation is carried out. Thus, for each discrete wavelength
presented in the spectrum, there should be defined complex refractive index in *.nk files
for all layers used in the simulation.
Advance Settings
By clicking the button Show Advanced settings following two options are possible to be
selected:
 Direct coherent light applied perpendicular to the structure
 Combination of perpendicular coherent specular light and incoherent diffused
light
Direct coherent light applied perpendicular to the structure
By selecting this option the illumination spectrum consists only of coherent specular light
applied perpendicularly to the structure.
Combination of perpendicular coherent specular light and incoherent diffused light
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By selecting this option the illumination spectrum is divided into two parts: direct
illumination and diffused illumination. The sum of both components is equal to the intensities
specified in the spectrum file.
The ratio diffused/(diffused + direct) has to be determined in the range 0 - 1. Value 0
corresponds to the presence of direct coherent component only (equal to selection of the first
option), whereas the value 1 corresponds to the presence of diffused component only (all light
of the spectrum is diffuesed).
For the diffused component of the spectrum angular distribution function (ADF) has to be
defined. The selection of ADF is the same as described in Angular Distribution Function
console for ADF1 (refer to ADF1R or ADF1T selection).
2.7 FILES
Output files and paths to all input and output files are specified in this console.
Basic Settings
Following files and folders can be defined:
 Name of the output files
 Folder of the output files
 Working folder <WORKDIR>
Name of the output files
In the text box the core (first, basic part) of the names of the output files is defined. The first
words that appear in all output files are represented by this core. Pre-defined extensions are
added to the output files by the simulator, depending on the type of the results (see more
details on the output files in the description of output files).
The name of the output files should meet all the requirements for the file names in Windows
XP. Additionally, it should not contain more than 50 characters. Spaces are allowed to be
used in the name of the output file.
The default name of the output files is set to SSOut (SunShine OUTput file).
At the bottom of the basic settings there exists a check box Ask if overwrite output files. If
the check box is activated, there appears a warning message if the output file with the same
name as specified in the text box already exists in the output folder (the box appears after
pressing run button). By lunching the simulator, the status of the check box is equal to the
status of last simulation.
Folder of the output files
Folder of the output files can be selected by Browse function or typed directly. A new folder
can be created by direct typing, if the root path to the folder that we want to create is valid
(already exists).
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The newly created folder should meet all the requirements for the file names in Windows XP.
Additionally, it should not contain more than 50 characters. Spaces are allowed to be used in
the name of the output folder.
Working folder <WORKDIR>
This is the folder where the simulator program is running. It was defined during the
installation of the simulator. The <WORKDIR> should not contain more than 6 levels of
folders.
The simulator detects automatically the path of the <WORKDIR>.
Check box Ask if overwrite output files
By checking this box the program asks you before running simulation whether you want to
overwrite the existing files in case their name is the same as current specification in the Name
of the output file box. After lunching the simulator's interface, the last setting of the checkbox
is used.
Advanced Settings
By clicking the button Show Advanced settings, following folders can be selected:






Folder with layer files (*.nk) (default: <WORKDIR>\nk)
Folder with calibration files (*.cal) (default: <WORKDIR>\cT_cR)
Folder with haze files (*.tis) (default: <WORKDIR>\HT_HR)
Folder with external ADF files (*.ars) (default: <WORKDIR>\ADF_external)
Folder with Illum. spectrum files (*.spk) (default: <WORKDIR>\Spectrum)
Folder with listing files (*.dat) (default: <WORKDIR>\List)
You can change the folders according to the locations of data on your computer. However,
use of default folders is recommended.
All folders can be selected by Browse function. In case of selecting non-default paths
<WORKDIR>, it has to be considered that the paths should not contain more than 6 levels of
folders.
Further advanced settings can be used:
 Assign paths to <WORKDIR> button
 Assign ALL paths to <WORKDIR> button
Assign paths to <WORKDIR> button
By pressing the button, paths of all folders specified in the advanced settings are assigned to
the current working folder <WORKDIR>.
Assign ALL paths to <WORKDIR> button
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This option is available with the same button if Ctrl key is pressed on your keyboard. By
pressing the button + Ctrl all paths in advanced settings and the path of output file in addition
are assigned to the current working folder <WORKDIR>.
ATTENTION: By importing an input file (File  Import Input File) also the paths to
the folders and files are imported. Check if the folder paths are set properly according
to your computer (especially by importing an input file created on other computer).
2.8 ADDITIONAL SETTINGS / COMMENTS
Calculation settings
Precision level of the calculation can be set. This level is related only to the stop condition in
tracing of the scattered light beams. The default setting is Normal.
Normal – in tandem structures (> 6 layers) the precision of the sum Alayers + R + T ≈ 1
(absorptances + reflectance + transmittance) can vary up to 3 % in this case.
High 
the sum Alayers + R + T = 1 varies les than 1 %.
In the case of many layer structures (like triple-cell) High level of precision can increase the
calculation time.
Additional comments (and settings if supported by the simulator version) can be written in
the text box. The text will be stored at the end of corresponding input file (as additional text).
2.9 PROCESS WINDOW
In this console messages related to the running (or previously running in case of finished
action) simulation are shown. The executed calculations for the wavelengths used in the
simulation are indicated on-line during simulations. Warning and error messages are
displayed in case of minor or major problems.
After pressing run button the process window console appears automatically on the screen.
The only exception is if we are located in the Result console.
If it is suspected that there is a problem with simulation, please check the messages in the
process window.
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2.10 RESULTS
Within this console main simulation results can be viewed as values in a table or plotted in a
graph.
The console contains following sections and settings:
 Show results
 Replace last on-line plots with new plots in next simulation
 Plot R/T/A Layer
 Jsc <photo>
 Graph legend
 Graph settings
 Graph button
 Table button
 Comments button
Show results
Select results for viewing. Following options can be selected by clicking down arrow on the
right side of the text box
 OnLine Results as selected below
 Selected output files: *.rta, *Spec.rta, *Dif.rta, *Gl, *.jph, *jsc, *_R.adf, *_T.adf
 IMPORT results
The default option is OnLine Results as selected below.
OnLine Results as selected below
Some of the main results of current simulation can be viewed on-line, while the simulation is
running or after it is finished. Selection of the on-line results should be done in the “Plot
R/T/A” and “Graph legend” areas. The results for selection are:
 Total Reflectance (specular + diffused) of the entire structure, R
 Total Transmittance (specular + diffused) of the entire structure, T
 Total Absorptance (specular + diffused) in each layer, A
 Short circuit current density <photo>, Jsc <photo> for particular layer.
In this case a simplified electrical analysis is taken into account to get output
characteristics of the solar cell directly from optical simulations. Simplifications
concern ideal extraction of all photogenerated charge carriers from the active layers. In
this case external quantum efficiency, QE (in some cases denoted with <photo>), of
the PV structure (e.g. a-Si:H pin solar cell) is found to be equal to the absorptance in
intrinsic (i) layer - in case of pin solar cell (see following equation).
QE photo  (i )  Aint (i )
From QE<photo>, Jsc <photo> is calculated as:
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J sc  photo   
i
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q
 I inc (i )  QE photo  (i )  i
hc
(h = 6.625·1034 Js, q = 1.6·10-19 As, Iinc is illumination spectrum, i discrete
wavelength represented in the spectrum, the sum refers to the sum of all discrete
wavelength components in the spectrum)
In PV active layers, Jsc <photo> presents a contribution to the common Jsc <photo>
of the structure. In case of non-active PV layer the Jsc <photo> values present optical
losses expresses in terms of Jsc <photo> (how much of Jsc<photo> is lost in the layer
according to potential Jsc<photo> that could be obtained from the given spectrum).
Selected output files (*.rta, *Spec.rta, *Dif.rta, *Gl, *.jph, *jsc, *_R.adf, *_T.adf)
Other results from selected output files of current simulation can be viewed after simulation is
finished. For details on the files refer to description of the output files in this manual.
IMPORT results
With this option the output files from previous simulations and other files in the standard
format of the SunShine output files (see description of output files in Section 3.2) can be
imported. For presentation of the results on the graph refer to the section Plotting external
output files.
Replace last on-line plots with new plots in next simulation
By selecting this option, the on-line plots of last simulation (and future simulations) will be
overwritten with the new plots obtained with next simulation. If not selected, the on-line plots
will remain on the graph, whereas the new results will be added as new plots. This option
becomes available after first simulation is finished.
Plot R/T/A Layer
This section refers to on-line simulation only. Total Reflectance (R) of entire structure, total
Transmittance (T) of entire structure and total Absorptance for specified layers can be
selected (check box) for plotting on the graph. The selection can be made before, during or
after simulation is finished (but before running next simulation). By changing the structure,
the layers in this column are changed automatically.
Jsc <photo>
This section refers to on-line simulation only. Corresponding values of short-circuit current
density Jsc<photo> are listed. They present either contribution to the actual Jsc <photo> of
the structure or losses expressed in terms of Jsc <photo>.
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Graph legend
The selected quantities from on-line simulations (Plot R/T/A Layer) and imported external
files are listed here. The colour of corresponding plots (lines) is shown. You can change the
colour by clicking on the corresponding coloured box  the colour palette will open and the
desired colour of the plot can be selected.
Each specified plot can be included or excluded from the graph by clicking corresponding
check box in front of the colour box.
By clicking the right mouse button on the name of selected plot, following options appear:
 Rename line and select vertical axis
 Remove line from graph
 Clear graph
Rename line and select vertical axis
New name can be entered in the box which appears. The name can be changed also by double
clicking left mouse button on the existing name. If the settings "Replace last on-line plots with
new plots in next simulation" is de-selected and a new simulation is run, the on-line results
from previous simulation will automatically get a pre-fix "Old" in case they have not been
renamed by the user.
The option select vertical axis is active only if secondary axis was added to the graph (see
Add / Remove secondary axis option on next page). Selection of left (default) and right
(secondary) axis with different scales is possible.
Remove line from graph
Selected plot is removed from the graph and legend.
Clear graph
All plots are removed from graph and legend.
Graph Settings
For horizontal (X) and vertical (Y) axis of the graph following settings can be determined:
 Min - minimal value
 Max - maximal value
 Step - defining the density of tick labels on axis)
 Label - name of axes, units
 Log - apply logaritmic scale
 Autoscale - autoscale the axis
The values are transferred into the graph window after pressing Apply button.
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Graph button
By pressing the button a graph with corresponding plots is activated.
Add / Remove secondary axis
These two options can be found by pressing right mouse button on the graph. They enable to
add and remove additional vertical axis on the graph, which appears on the right side of the
graph if at least one plot is assigned to the axis (see option Select axis in Graph legend
description).
Table button
By pressing the button a table with corresponding values of
 R, T and A results of on-line simulation or
 data from other output files selected by Select results option
can be viewed.
At the top left corner of the table window, the button Add line to graph is located.
Add line to graph button
By pressing the button, a Select axis box appears on your screen. X and Y axis of the new plot
can be determined from the data in the table in two ways:
 by clicking the down arrow at the right side of the text box for determination of X or
Y axis and selecting the name of the column from the table
 by clicking inside the text box for determination of X or Y axis and then clicking on
the desired column directly in the table.
After selecting X and Y data, the added plot should appear in the graph (press the Graph
button to switch to the graph window). In Graph Legend section there should appear the
corresponding name with the prefix ext. You can change the plot colour in the Graph Legend
window (refer to the description of Graph Legend).
NOTE: If the existing minimal and maximal values of the graph axes are out of the
range regarding to the values to be plotted, the plot will not be shown. Adjust the
minimal and maximal values of the axes appropriately.
To exclude the external plot from the graph click in the corresponding check box. To remove
the external plot completely from the graph, click the name of the plot with right button of the
mouse and select Remove line from graph.
Comments button
Comments to the results can be written in the corresponding box. The comments are plotted
together with the results if using "File > Print results" option. They are not stored with the
input file!
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Additional tips:
Plotting on-line results (R/T/A)
Graph button should be switched on.
Select the desire quantity to be plotted by activating the corresponding check box in the Plot
R/T/A Layer section. If the graph settings (axes) are set appropriately, plots should appear on
the graph during or after running the simulation.
Plotting external output data
Select the desire output file in the Select Results option using Browse. Press the Table
button on bottom left side of the console.
By pressing the Add line to graph button, a Select axis box appears on your screen. X and Y
axis of the new plot can be determined from the table in two ways:
 by clicking the down arrow at the right side of the text box for determination of X or
Y axis and selecting the name of the column from the table or
 by clicking inside the text box for determination of X or Y axis and then clicking on
the desired column directly in the table.
After selecting X and Y data, the added plot should appear in the graph (press the Graph
button to switch to the graph window). In Graph Legend section there should appear the
corresponding name with the prefix ext. You can change the plot colour in the Graph Legend
window (refer to the description of Graph Legend).
3. DESCRIPTION OF FILES
Structure of input and output files is described. All input and output files can be viewed as
normal text files.
3.1 Input files
There are following input files:
 *.nk files
 *.cal files
 *.brc files
 *.tis files
 *.ars files
 *.spk files
 listing files: layer.dat, cT.dat, cR.dat, ReflCal.dat, HT.dat, HR.dat, ADF1ext.dat,
ADF2ext.dat
and *.txt input file with haze measurements (created by user) for the cR_cT transform, which
description is given in the first part of section 2.
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*.nk files
Complex refractive indexes N = n - jk (n - refractive index and k - extinction coefficient) as a
function of discrete wavelength (lambda) are determined for specific layer. Beside n and k
values, absorption coefficient (alpha) is given in the file (alpha = 4*PI*k/lambda).
The structure and requirements of the file are explained on the following example of i*.nk file
(only the first part of the file is given)
~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
layer1
lambda
nm
n
k
alpha
1/cm
300.0
305.0
310.0
315.0
320.0
325.0
330.0
335.0
340.0
345.0
350.0
3.748
3.815
3.883
3.949
4.015
4.079
4.143
4.205
4.267
4.324
4.382
3.140
3.125
3.110
3.085
3.060
3.000
2.940
2.855
2.770
2.685
2.600
1315280.124
1287985.427
1260690.729
1231174.960
1201659.190
1160604.286
1119549.382
1071669.494
1023789.606
978645.712
933501.817...
In the header the description of layer and data (columns) is given. It can be changed by the
user, except the word alpha, nm (or um) and the last word "1/cm" should remain. After the
word "1/cm" the four numerical columns should appear.
There are four columns specified. The order of the four columns has to be as follows:
1.) lambda - wavelength in nano (or micro)meters, depending on selection of nm or um in
the heading row (previous versions of SunShine allows only micrometers)!
2.) n
3.) k
4.) alpha - absorption coefficient in 1/cm
All four columns are necessary to be in the file.
The decimal separator for the numbers should be dot ("."). The numbers may include more
than two decimal places. The separators between columns can be either spaces or tabulators.
The file ends with the last numbers of the columns.
Note: Simulations can be carried out only for the discrete wavelengths that are
represented in the *.nk files.
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*.cal files
Haze calibration functions (cT and cR) as a function of discrete wavelength and rms
roughness (sr), as a parameter, are given in *.cal files (separate files for cR and cT).
The structure and requirements of the files are explained on the following example of
cT_05.cal file (only the first part of the file is given). The structure of the cR file looks the
same.
~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
cT_05
No of roughnesses (sr): 1
lambda(nm)
300.0
305.0
310.0
315.0
320.0
325.0
330.0
335.0
340.0
345.0
350.0
...
sr(nm)=50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
The header text before the row "No of roughnesses:" can be changed, but should not contain
any colon ":"!
The number of cT (cR) columns has to be specified in the line "No of roughnesses (sr)" which
should end with a colon ":", before number is given. Each sr roughness has to be specified
above corresponding cT (cR) column after "=" sign.
The order of the columns has to be as follows:
1.) lambda - wavelength in nanometers
2.) cT (or cR in case of cR files) values for corresponding rms roughness (sr)
3. and rest.) cT (or cR in case of cR files) values for the next rms roughnesses (sr)
The decimal separator for all numbers should be dot ("."). The numbers can include more than
one decimal places. The separators between columns can be either spaces or tabulators. The
file ends with the last data of the columns.
Note: If certain *.cal file is included in the simulation, all the discrete wavelengths of the
selected input spectrum should be represented also in the *.cal file, while for the
roughnesses linear interpolation between the specified sr values is used in the simulator.
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*.brc files
Total reflectance calibration function (or total reflectance directly - see description of Total
reflectance and transmittance console \ Advanced settings) from the front side of the interface
(c12) as a function of discrete wavelength and rms roughness (sr), as a parameter, are given in
*.brc files. c12 values should be in the interval between 0 and 1.
The structure and requirements of the files are explained on the following example of
BRcor_08_09.cal file (only the first part of the file is given).
~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
BRcor_08_09
No of roughnesses (sr): 1
lambda(nm)
300.0
305.0
310.0
315.0
320.0
325.0
330.0
335.0
340.0
345.0
350.0
...
sr(nm)=50
0.80
0.80
0.80
0.80
0.80
0.80
0.90
0.90
0.90
0.90
0.90
The header text before the row "No of roughnesses:" can be changed, but should not contain
any colon ":"!
The number of c12 columns has to be specified in the line "No of roughnesses (sr)" which
should end with a colon ":" before the number. Each sr roughness has to be specified above
corresponding c12 column after "=" sign.
The order of the columns has to be as follows:
1.) lambda - wavelength in nanometers
2.) c12 values for corresponding rms roughness (sr)
3. and rest) c12 values for the next rms roughnesses (sr)
The decimal separator for all numbers should be dot ("."). The numbers can include more than
one decimal places. The separators between columns can be either spaces or tabulators. The
file ends with the last data of the columns.
Note: If certain *.brc file is included in the simulation, all the discrete wavelengths of the
selected input spectrum should be represented also in the *.brc file, while for the
roughnesses linear interpolation between the specified sr values is used in the simulator.
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*.tis files
Haze data (HT or HR) as a function of discrete wavelength and rms roughness (sr)
(parameter), are given in *.tis files.
The structure and requirements of the files are almost equal than in the case of *.cal file.
Thus, here only the differences will be explained - for other requirements refer to description
of *.cal files.
Example of HT_01_ZnO_Al_air.tis file. The first part of the file is given in following:
~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
HT_01
Incident layer: TCO_ZnO_Al
Layer in transmission: air
No of roughnesses (sr): 1
lambda(nm)
sr(nm)=50
300.0
310.0
320.0
330.0
340.0
350.0
0.10
0.10
0.10
0.10
0.10
0.10
The differences regarding to *.cal files are the two additional lines (written in bold here).
In the first line "Incident layer" the name of the incident layer corresponding to the measured
haze data should be given. The name should follow after the colon ":" sign at the end of
"Incident layer" text.
For details on the name of the layers refer to description of layers in Structure section.
In the second line "Layer in transmission" the name of the layer in which the light is entering
with the corresponding haze data should be given. The name should follow after the colon ":"
sign at the end of "Layer in transmission" text.
For details on the name of the layers refer to description of layers in Structure section.
Note: If certain *.tis file is included in the simulation, all the discrete wavelengths of the
selected input spectrum should be represented also in the *.tis file, while for the
roughnesses linear interpolation between the specified sr values is used in the simulator.
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*.ars files
External Angular Distribution Functions (ADF1T, ADF1R, ADF2T, ADF2R) of scattered
light as a function of discrete scattering angle (fi_scat) is given in *.ars files. Further
parameters are incident angle of illumination beam (fi_inc) and rms roughness (sr) of the
rough interface on which the ADF was determined.
The structure and requirements of the files are explained on example of ADF2R_unity.ars
file. The contents of the file is given in the following.
~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
ADF2R unity
Incident layer: undefined
Layer in transmission: undefined
No. of scattering angles (fi scat): 8
No of incident angles (fi inc): 2
No of rms roughnesses (sr) : 2
sr(nm)=50
fi_scat(deg)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
fi inc (deg)=0
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
fi inc (deg)=30
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
sr(nm)=100
fi_scat(deg)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
fi inc (deg)=0
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
fi inc (deg)=30
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Header text before the line "Incident layer" can be changed by user, but the text should not
contain colon ":" sign.
In the header lines "Incident layer" and "Layer in transmission" the corresponding two layers
forming the interface are defined in the same way as in case of *.tis files (for details refer to
description of *.tis files)
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In the next header line "No. of scattering angles (fi scat):" the correct number of discrete
scattering angles that appear in the file has to be specified after the colon ":" sign.
In the header line "No of incident angles (fi inc):" the correct number of discrete incident
angles that appear in the file as different columns has to be specified after the colon ":" sign.
In case of ADF1, typically only one incident angle is specified (at zero degrees)
In the header line "No of rms roughnesses (sr):" the correct number of discrete rms
roughnesses that appear in the file as different data sections has to be specified after the colon
":" sign.
The text above the header row "No. of scattering angles (fi scat):" can be changed but should
not include colon ":" sign.
The data sections referring to different rms rougnesses (sr) should be organised in following
way.

First the corresponding rms roughness (sr) in nanometers should be determined after
"=" sign.

After the name fi_scat (deg), incident angles should be defined in degrees for each
column, following the "=" sign (fi_inc (deg = ).

In the first column the values for incident angles has to be defined in degrees. The
number of rows should correspond to the specified number of scattering angles.

In all other columns the ADF values for corresponding scattering and incident angle
are given.

For other rms roughnesses (sr) new data sections has to be created. They should have
the same structure as the section described. The scattering angles fi_scat and incident
angles fi_inc have to be the same in al sections.
The ADF data given in *.ars files does not need to be normalised (sum of ADF values over all
discrete angles is not necessary to be one), since the normalisation is performed in the
simulator internally.
Note: The ADF data in *.ars files should already include ADF transformations (e.g. 3D,
1D transformation, transformation for conical illumination). For these data the
transformations are not performed inside the simulator.
*.spk files
Illumination spectrum (power densities) as a function of discrete wavelength is defined in
*.spk file.
The structure and requirements of the files are explained on example of ADF2R_unity.ars
file. The first part of the file is given in the following:
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~~~~~~~~>
~SunShine~>
~~~~~~~~~~~>
AM1.5
No of used components in the spectrum: 81
Wavelength
lambda
nm
Power density
I
mW/cm2
300.0
310.0
320.0
330.0
340.0
350.0
...
0.001
0.102
0.257
0.391
0.430
0.478
The header text before the line "No of used components" can be changed by user, but should
not contain any colon ":" sign.
In the header line "No of used components in the spectrum:" number of spectrum components
that will be used for the simulation has to be defined after colon":" sign. The first used
component is always the first component defined in the spectrum.
The text about this header line can be changed but should not include any colon ":" sign.
The header should end with the keyword "mW/cm2". After this word, the data in two columns
should start:
1.) lambda - wavelength in nano (or micro)meters, depending on selection of nm or um in
the heading row (previous versions of SunShine allows only micrometers)!
2.) Intensity (power density) in mW/cm2 corresponding the single wavelength or wavelength
interval in case of continuous spectrum.
The decimal separator for the numbers should be dot ("."). The numbers can include more
than two decimal places. The separators between columns can be either spaces or tabulators.
The file ends with the last row of the four column.
Listing files
The listing files contain a list of options for specific input parameters that can be selected in
the text boxes by clicking the down arrow on the right side of the corresponding box.
There are following listing files:
layer.dat, cT.dat, cR.dat, ReflCal.dat, HT.dat, HR.dat, ADF1ext.dat and ADF2ext.dat.
Their names indicate to which input parameter they refer to.
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Example of layer.dat listing file is given in the following:
Ag
air
Al
glass
i_a_SiH
n_a_SiH
p_a_SiCH
TCO_SnO2_Asahi
TCO_ZnO_Al
Usually, these are the names of the source files (without extensions) with the corresponding
data. The listing files can be changed by the user. Each new option has to be specified in a
new row. No empty rows are allowed between the specified options.
By making new data input file (e.g. new *.nk file) the name should be added in the
corresponding listing file by the user.
3.2 Output files
There are following output files available:
 *.rta
 *Spec.rta
 *Dif.rta
 *.Gl
 *ASA.gen
 *.jph
 *.jsc
 *Sum.jsc
 *R.adf
 *T.adf
 *.hrt
 *_ratio.jph
 *_optimo_iter.out (result of the Optimisation tool)
 *_optimo.out (result of the Optimisation tool)
 *.lif (result of the transform Calculate LPIF)
*.rta file
The file contains simulation results on total reflectance from entire structure (Rtot), total
absorptances (Atot) in individual layers and total transmittance (Ttot) of the structure, as a
function of wavelength (l).
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The example of the first part of an *.rta file is given in the following:
l[nm]
300.0
310.0
320.0
330.0
340.0
350.0
...
Rtot Atot1_glass Atot2_TCO_SnO2_Asahi
0.0471
0.6271
0.3252
0.0502
0.4732
0.4628
0.0539
0.3391
0.5259
0.0586
0.2359
0.4892
0.0653
0.1625
0.3948
0.0713
0.1108
0.3000
Atot3_p_a_SiCH
4.0400e-4
8.6310e-3
0.0503
0.1316
0.2229
0.2960
A simple header (one line) with the column names is chosen due to simplicity of importing
data in other programs.
The columns are organised as follows:
1.) l - wavelength in nanometers
2.) Rtot - total reflectance of entire structure
3.) Atot - total absorptances in each layer
...
last column.) Ttot - total transmittance of entire structure
The names of the columns with total absorptances consist of "Atot"_"layer index No"_"layer
name".
The decimal separator is dot ".". The separator between columns is tabulator.
*Spec.rta file
The file contains simulation results on specular reflectance from entire structure (Rspec),
specular absorptances (Aspec) in individual layers and specular transmittance (Tspec) of the
structure, as a function of wavelength (l).
The structure of the file is equal as in case of *.rta files (please refer to description of *.rta
files).
*Dif.rta file
The file contains simulation results on diffused reflectance from entire structure (Rdif),
diffused absorptances (Adif) in individual layers and diffused transmittance (Tdif) of the
structure, as a function of wavelength (l).
The structure of the file is equal as in case of *.rta files (please refer to description of *.rta
files).
*.Gl file
The file contains simulation results on photogenerated charge carriers (Gl) as a function of
vertical position in the structure, x. The parameter is light wavelength (l).
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The Gl values are calculated and given only for the layers which were selected as PV active in
the Structure console.
The example of the first part of an *.Gl file is given below:
In the header basic information about the illumination spectrum are given. In the row above
the columns the wavelength parameter (l) is defined for each of the Gl column.
The columns are organised in the following way:
1.) x - position of the discrete point in the structure in nanometers. It starts with the first point
of the first PV active layer.
3. and rest columns) Gl - photogenerated charge carrier values for a specific point and
wavelength in 1/(cm3s)
The Gl values that are given in the calculation points correspond to the spaces (Gl segm.)
defined in the following figure.
Gl
segm.




calculation points
NOTE: For accurate representation of Gl, sufficient number of calculation points (No.
of Segm) has to be defined for the PV active layers in the Structure console.
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*ASA.gen file
In this file the generation rate data are arranged in the format that can be directly read by
Advanced Numerical Simulator - ASA 6 simulator (developed at Delft University of
Technology), which can be used as an option for further electrical analysis of the
optoelectronic structures.
*.jph file
The file contains simulation results of total light intensity (I) (specular + diffused, sum of all
forward and backward going components) as a function of vertical position, x, in the
structure. The parameter is discrete light wavelength (lambda) taken from the illumination
spectrum.
The example of the first part of an *.jph file is given in the following:
The structure of the file is equal to the one in *.Gl file (refer to description of *.Gl files) with
following exception: light intensity is specified at each discrete calculation point in the
structure. The corresponding absolute position x of each discrete calculation point is given.
The specified intensities correspond exactly to these positions.
NOTE: For accurate representation of light intensity profile across the structure,
sufficient number of calculation points (No. of Segm) has to be defined for the layers in
the Structure console.
*.jsc file
The file contains simulation results of short circuit current densities, Jsc <photo>, as a
function of discrete wavelength. In such a way the contribution of specific wavelength to the
common Jsc <photo> is indicated.
For determination of the Jsc <photo> values from optical simulations refer to Results section.
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The structure of the file is the same as in case of *.rta file (refer to the description of *.rta
file). Jsc <photo> values are given in mA/cm2.
*Sum.jsc file
The file contains simulation results of short circuit current densities, Jsc <photo> for each PV
active and non-PV active layer. Corresponding values of Jsc <photo> are given also for
reflectance and transmittance. In case of PV active layers the Jsc <photo> values contribute to
the actual Jsc <photo> of the structure, whereas in case of non-PV active layers (incl.
reflectance and transmittance) these values are assigned to the losses expressed in terms of Jsc
<photo>. For the calculation of Jsc <photo> refer to description of Results console.
Example of *Sum.jsc file:
Jsc
mA/cm2
layer
6.770 Rtot (losses)
0.140 glass (losses)
5.204 TCO_SnO2_Asahi (losses)
2.173 p_a_SiCH (active)
16.003
i_a_SiH (active)
0.791 n_a_SiH (active)
1.217 Ag (losses)
0.000 Ttot (losses)
-----------------------------------------32.284
Jsc Total Sum
18.953
Jsc Active Layers
*R.adf file
In this file the power densities of the diffused reflected light from entire structure as a
function of outgoing angle are given in mW/cm2. The power densities are calculated at the
angles from  900 to 900 (00 - normal direction) in the incident plane (perpendicular to the
interfaces of the structure) at the distance (radius) of 50 cm from the structure. To re-calculate
these power densities to other radius, R, the multiplication factor MF = 502 cm2/R2 cm2
should be applied to the values. The number of equidistant angles is defined by the parameter
"Number of equivalent angles per 90 degrees" in the Angular Distribution function console.
The wavelengths are defined by the spectrum used.
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The example of the *R.adf file is given below (only the first part of the file).
The power densities in this file are directly comparable with the power densities measured
with an Angular Resolved Scattering (ARS) setup in an incident plane, with the lenght of
rotating arm of 50 cm (for description of ARS measurements refer to documentation on
Scattering parameters).
*T.adf file
In this file the power densities of the diffused transmitted light through entire structure as a
function of outgoing angle are given in mW/cm2. The power densities are calculated at the
angles from  900 to 900 (00 - normal direction) in the outgoing plane (perpendicular to the
interfaces of the structure) at the distance (radius) of 50 cm from the structure. To re-calculate
these power densities to other radius, R, the multiplication factor MF = 502 cm2/R2 cm2
should be applied to the values. The number of equidistant angles is defined by the parameter
"Number of equivalent angles per 90 degrees" in the Angular Distribution function console.
The wavelengths are defined by the spectrum used.
The example of the *T.adf file looks similar to the example of *R.adf file from previous
section.
The power densities in this file are directly comparable with the power densities measured
with an Angular Resolved Scattering (ARS) setup in an outgoing plane.
*.hrt file
Calculated haze of the reflected light of the entire simulated structure and of the transmitted
light through the structure are presented as a function of incident light wavelength. First column
is light wavelength in nanometers, second column is haze for reflected light (HRstructure, 0 .. 1)
whereas the third column is the haze for the transmitted light(HRstructure, 0 .. 1).
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*_ratio.jph
Ratios of total light intensities at the end of the layers (I(d)) over the total intensities at the
beginning of the layer (I(0)) are given as a function of light wavelength for each layer in the
structure. These ratios are used in the calculations of Light Path Improvement Factor  LPIF.
Refer to the description of the Calculate LPIF tool.
*_optimo_iter.out file (result of the Optimisation tool)
This is the output file, where the results of each iteration in the optimisation process are
stored. The file is organised as follows:
1. column: Iteration number
2. set of columns: the values of the input parameters (or corresponding factors) which were
involved in the optimisation
In the case of roughness optimisation in this file only the roughness values for the first
selected interface is printed out (the optimal roughness values for all selected interfaces are
plotted in the *_optimo.out file).
3. last column: Jsc<photo> values of the selected layer(s) for the Jsc<photo> optimisation
- if one layer was selected then this are the Jsc<photo> values of this layer
- if more layers were selected and the criteria of minimal or maximal Jsc<photo> was
chosen these values represents the sum of the Jsc<photo> of the selected layers
- if two layers were selected and the criteria of minimal difference in Jsc<photo> was
chosen then these values represents the difference in Jsc<photo> between the first and
the second selected layer
The file is updated after each SunShine iteration.
*_optimo.out file (result of the Optimisation tool)
This is the final output file of the optimisation process including the list of the optimal values of
the input parameters that were chosen for the optimisation. Indications on which input
parameters were varied (optimised) and which criteria and Jsc<photo> values were used.
The file is created after the optimisation is finished.
*.lif file (result of the Calculate LPIF tool)
Light Path Improvement Factors – LPIF as a function of the wavelength are listed. For the
details of calculation refer to the description of the Calculate LPIF tool.
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4. SIMULATION EXAMPLE
A standard pin amorphous silicon (a-Si:H) solar cell, deposited on textured glass/TCO
substrate is given as an example of simulation. A standard selection of input parameters for
the structure is used.
By means of described procedures for entering and choosing input parameters in specific
consoles (Structure, Haze parameters, Angular Distribution Functions, Total Reflectance and
Transmittance, Illumination Spectrum, Files, Additional Comments/Settings, Process
Window and Results) one can create the example structure by his own, using the input
parameters of the structure given by the following pictures of each console.
NOTE: When running the example file from the existing input file
\\SinShine\In\Example v1_2_8.dat, first in the Console FILE all the paths have to be
checked/properly assigned to the working directory on your computer (see point 6 in the
following figures). All paths can be assigned by pressing “Ctrl” and clicking on the
“Assign paths to <WORKDIR>” button.
1.) Structure
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2.) Haze parameters
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3.) Angular Distribution Functions
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4.) Total Reflectance and Transmittance
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5.) Illumination Spectrum
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6.) Files
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7.) Additional comments/settings
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8.) Process Window (after simulation is finished)
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9.) Results (after simulation is finished)
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APPENDIX 1
Optimisation tool of SunShine v1.2.8 simulator
Numerical method description:
The methods in the optimisation tool – OPTIMO are based on the following three numerical
techniques for finding an extreme (minimum or maximum):
 Simulated annealing
 Simplex
 Method of constant steps
These techniques are generally used in numerical optimisation tools.
Reference: W.H. Press, S.A. Teukolsky, W.T. Vetterling, B.P. Flannery, Numerical Recipes
in C++: The Art of Scientific Computing, Cambridge University Press, 2nd ed., 2002..
Short description of the techniques:
Simulated annealing
The idea of this technique is to apply a “temperature” (increasing the output value by a
weighted random value – introduction of a random component) to the intermediate solutions
and than slowly decreasing its influence (the weight is getting smaller so that the random
value is loosing the effect on the output value). In this way the solution can get trapped inside
the deepest hole (minimum) with the global solution The strategy for finding a maximum is
similar). In the case that the solution falls in a local minimum the “temperature”
(randomisation component) is usually high enough to knock it out. The probability of finding
a global minimum (extreme) is higher for slower cooling and higher temperatures. Simplex
techniques (described later) is the variant of simulated annealing technique with the
temperature of 0. In our tool we have built in 3 different preset methods:
1. Simulated annealing with high probability (slower method, high probability of finding
a global extreme)
2. Simulated annealing with normal probability
3. Simulated annealing with low probability (faster method, high probability of finding a
local extreme)
Pros
Method can find a global extreme.
Cons
It can be a time-consuming method.
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Simplex (Nealder-Mead method)
Method always finds a local extreme, global optimisation is not possible! In N-dimensional
space the method uses a simplex (geometrical figure) with N+1 vertices [1]. The key issue of
the method is to move the simplex with N+1 vertices downhill to the minimum or uphill to a
maximum. In many of our cases (simulations) we have only one extreme, which is also the
global extreme in the constrained domain. Figure A1 presents the simplex method in 1
dimensional space (1D) – one input optimisation parameter. In the first step N+1 vertices of
simplex are calculated (the value of the first vertex is calculated in the middle point of the
constrained domain – red star, the second one is calculated closely to the right boundary of
the constrained domain – black point). The method moves the vertex with the worst value (in
our case of minimization, the vertex with highest output value) downhill to the minimum by
so called extension, contraction or reflection of the highest point. In the first step the vertex
with black point is contracted around the lowest point. The point 2 is better than the black
point 1, so the black point vertex of the simplex is now moved to the point 2. In the next step
the red star vertex of the simplex has worse value, therefore the next red star vertex is now
beeing searched by the contraction, reflection or extension leading towards better solution.
These steps are repeated until the sufficient accuracy (closeness of the solutions) is achieved.
output
constrained domain
start
1
start
1
2
3
4
end
global extreme - solution
optimised variable(s)
Figure A1: Illustration of finding a solution with simplex method. The method has much
better convergence rate than the method of constant steps. Increasing the number of steps
always means a better accuracy.
Pros
The method is very fast, especially for multi-dimensional problems, when we have to
optimise more parameters. Recommended method!
Cons
Always finds a local extreme, which is not necessary a global one.
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Method of constants steps:
The method of constant (equidistant) steps scans the parameter area in the predefined points
(Figure A2). This method is straight forward or brute force method. Method scans the whole
area without any prediction of a new direction where the solution might occur. In case the
method scans over the solution, it does not stop. Due to equidistant discrete steps the finer
mesh does not always mean more accurate solution. It is not recommended to use the method
of constant steps in multidimensional region (when the optimal values of more than one
variable are searched, for instance roughness and thickness). Relative error does not apply to
this method! The user have to define the number of steps, which are applied to all dimensions.
output
constrained domain
start
1
1
2
2
3 4
end
3
5
5
6
solution for 6 steps 4
and for 11 steps
7
6
10 11
9
8
global extreme - solution
optimised variable(s)
Figure A2: Illustration of finding a solution with method of constant steps. It is not necessary
the finer mesh will give a better solution.
Pros
Method can find a global optimum in presence of many extremes.
It can be applied in sensitivity analysis, parameter variations.
Cons
Time-consuming method, generally not recommended method.
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APPENDIX 2
1) FTDI drivers Installation guide for Windows XP
2) FTDI drivers Installation guide for Windows Vista
3) FTDI drivers Installation guide for Windows 7
(source: http://www.ftdichip.com)
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