Published online by Cambridge University Press: 09 January 2013
Despite organic solar cells have recently shown remarkable high power conversion efficiencies approaching 10%, further improvements are required to provide a low-cost alternative to inorganic photovoltaics. Optical losses related to insufficient light trapping and parasitic absorption of the contact layers limit drastically the photocurrent delivered by the cells. Textured surfaces, such as V-grooves (2D) and pyramids (3D), can provide better light coupling into the conformally deposited solar cells. In this work, we analyze the enhancement in light absorption in textured solar cells based on copper phtalocyanine (CuPc) and fullerene (C60) on the micro- and submicroscale. The analysis is carried out with the aid of the finite element method in 2D and 3D, taking into account interference as well as reflection and refraction of the incident AM1.5G spectrum. The results show that both type of structured cells perform better than planar cells reaching up to 23% improvement in maximum photocurrent for normal incidence. We also explore the lateral inhomogeneities of the generation rate within the active layers and their potential effect on the exciton collection efficiency.