Simulation of light intensity dependent current characteristics of polymer solar cells

An extended replacement circuit describing the current-voltage characteristics of bulk heterojunction polymer solar cells at different light bias levels is introduced and discussed. A one diode-model is expanded by an extraction model for photogenerated carriers taking into account the effective reduction of the mean distance which the charge carriers cover when sweeping the electrical bias through the fourth quadrant of the solar cell. The model properly describes the current-voltage behavior of bulk heterojunction solar cells over more than three orders in light intensity with one set of parameters. (C) 2004 American Institute of Physics.