The following program fits your characteristic IV-data according to the one diode model. You can download it and run the executable file. The source code can be found on GitHub.
solarcell_diodemodel_fitting Executable program that automatically fits exponential I-V curves of solar devices. solarcell_diodemodel_fitting.exe (2.69MB)
solarcell_diodemodel_fitting Executable program that automatically fits exponential I-V curves of solar devices.