Simplified numerical simulation of organic photovoltaic devices

Finite-element modeling for efficient organic bulk-heterojunction photovoltaics is presented. Given the complexity of the architecture, it has been hard to devise a sufficiently compact description of the physics of charge and exciton dynamics. This paper delineates the most essential set of equations that allow to reproduce the major characteristics of a current---voltage curve measured under illumination. Parameters are extracted by optimization of a fabricated polymer/fullerene cell, and by deliberately changing key parameters, further understanding is established on the phenomenological manifestation of independent physical processes.