Generalized theory for analytical simulation of the steady-state photocarrier grating technique

Abstract

The steady-state photocarrier grating technique has become a valuable method for determining minority-carrier μτ products of amorphous semiconductors. Here we introduce a generalized theory which is not a priori based on ambipolar transport and which describes the influence of the external electric field besides the grating period on the deduced coefficient β. The coefficient β is a measure of the change in the photocurrent with the appearance of the grating in the photogeneration rate. This novel analytical approach is verified by numerical simulations and is successfully applied to experimental data. More insight is gained into the transport processes in amorphous semiconductors which are of substantial importance for amorphous solar cells.