PV-jV- Analysis
The determination of diode parameters of illuminated and dark solar cells is a difficult task because, for instance, the function of the current becomes implicit by a non-zero series resistance. Furthermore, the shift of illuminated j-V curves of solar cells into dark ones with the help of the short circuit current can lead to inaccurate interpretations. It was shown that the photo current, this is the short circuit current times the collection efficiency, is in general voltage dependent. To account for this voltage dependency one has to determine experimentally the collection efficiency. This can be done by measuring j-V curves under incremental light intensity.
We developed two programs to automate the analysis of experimental data. The determination of diode parameters is differentiated into the dark (PV-jV-Dark.nb) and the illuminated (PV-jV-Light.nb) case. Both programs are enclosed in a graphical user interface in Wolfram Mathematica. The diode parameters of illuminated and dark solar cells can be computed stepwise or by a fit of the entire dark curve. For the second case, we established another program (PV-jV-DiodeFit.exe for Windows) being implemented in a Fortran code, which uses numerical solutions of the implicit current function. It can be executed in a Windows or Linux operating system. The execution of this program is adopted in the graphical user interface, nonetheless it can be used in a terminal on its one.
If you would like to use this FREE software package PV-jV-Analysis, please contact us: florian.obereigner@googlemail.com.