Three-Dimensional Optoelectronic Model for Organic Bulk Heterojunction Solar Cells

This paper describes a 3-D optoelectronic device model for organic bulk heterojunction solar cells. Three-dimensional full-wave optical simulation enables us to incorporate different modern light trapping techniques, such as subwavelength nanostructures, in a typical organic bulk heterojunction solar cell, while 3-D electrical simulation allows us to handle localized enhancement or reduction of polaron/charge generation, recombination, and transport induced by modern light trapping techniques in the device. We calibrate our model with an experimental poly (3-hexylthiophene) (P3HT):phenyl-C₆₀-butyric acid methyl ester (PCBM) organic bulk heterojunction solar cell by tuning only one free parameter as compared with other device models, which have multiple fitting parameters. A 3-D example of a silver nanoparticle array in a typical P3HT:PCBM organic bulk heterojunction cell is also demonstrated, and the current density-voltage relation is predicted with our model.