2/3-Diode Fit

By Stephan Suckow

RWTH Aachen



Published on


This download provides the program "2/3-Diode Fit", which can be used to interactively simulate or fit I-V characteristics of solar cells using different 2- or 3-diode models. Diff erent file formats and batch processing are supported as well as di fferent modes: dark or illuminated I-V curve fi tting, variable ideality factors, Suns-Voc, single diode models and an extended 2-diode model taking into account the distributed nature of a part of the series resistance according to a model developed by Breitenstein and Rißland. Alternatively the 3-diode model according to Hernando and McIntosh can take increased series resistance in the path of the 3rd diode into account. This functionality is complemented by the ability to plot and fi t the local ideality factor. The program features a polished graphical user interface, multi language support and can be run using MATLAB or as stand-alone executable under Windows (32/64 bit) or Linux (64 bit).

To get started you should download the file "manual.pdf" and consult section 3.1. There, the two different methods to install the program are explained. Depending on which way you choose you should download diff erent fi les and you should not need to download the entire 1 GB.

You are allowed to use, share and adapt the work for non-commercial purposes under a similar license, as long as you attribute its origin (see http://creativecommons.org/licenses/by-nc-sa/3.0/ for details). Anything else requires permission from the author.

Last update: 04 December 2014, Version: 2.3.13
(Note: currently the distributed MATLAB version is still 2.0.8.)

Sample screenshot:


Thanks go to E. Stegemann for the first version of the program and to O. Breitenstein, S. Rißland, N. Wilck, M. Thore and D. Nielinger for enduring beta-testing, as well as various other people for finding and reporting smaller bugs. Special thanks go to M. Raval for bringing up and testing the resistance limited recombination model. Further thanks go to J. Blass, A Gorodnichev, K. Razavidinani and J. Xie for the first implementation of the Breitenstein-Rißland model and to T. Pletzer for continued support and feedback.


  • Suckow S, Pletzer TM, Kurz H. Fast and reliable calculation of the two-diode model without simpl ifications. Progress in Photovoltaics: Research and Applications 2014, 22(4), 494–501. DOI: 10.1002/pip.2301.

Cite this work

Researchers should cite this work as follows:

    • Sven Rißland, Otwin Breitenstein. Considering the distributed series resistance in a two-diode model. Energy Proceedia 2013, 38, 167-175. DOI: 10.1016/j.egypro.2013.07.264.
  • Stephan Suckow (2014), "2/3-Diode Fit," https://nanohub.org/resources/14300.

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