The interface recombination current of the CdS/CdTe heterojunction solar cell

Abstract

The recombination current and its relation with voltage and density of interface states of the CdS/CdTe solar cell are discussed. Interface state is the result of lattice mismatch of the two materials used. Here, we regard interface states as impurity lever. In order to find out its influence to the efficiency of solar cell, we use S-R-H model to calculate interface recombination current of the cell on illumination conditions. At the same time, interface recombination current density is compared with photo-generated current density and we find that it is the main loss for thin cell. Also, we discuss relation between interface recombination current and capture cross-section and other factors, we find that interface recombination current is significant when the photo-voltage changes from 0.5V to 0.7V. If photo-voltage is less than 0.5V, interface recombination current could be neglected. At last, we analyze the way to reduce interface recombination current.