Determination of the optimal bandgap of a polymer in bulk heterojunction solar cells

Abstract

The aim of this paper is to determine the optimal bandgap of a polymer used as a photo- active material in bulk heterojunction solar cells in order to maximize the power conversion efficiency of the device. We have considered an ideal absorption profile for the photoactive material and we calculated the maximum current output of the device as a function of the polymer bandgap. Since the open circuit voltage depends on the position of the frontier orbitals of the donor and the acceptor, we also took in account acceptors with different LUMO levels.