Simulation of electron-beam-induced-current profiles for thin-film heteroj unction analysis

Abstract

The application of the electron-beam-induced-current (EBIC) method to thin-film heterojunction solar cells is discussed. The aim is to extract the effective minority carrier diffusion length L_eff in the absorbing layer of the cell which is closely related to the diffusion length of light-generated charge carriers. Current versus primary electron energy profiles for the planar EBIC configuration are simulated by considering the effect of back-surface recombination and backscatter-ing of primary electrons at the back contact. It is shown that for an absorber layer with thickness in the range of the diffusion length, the accuracy limit for the determination of L_eff is reduced to 30% owing to the influence of interface recombination at the back contact.