Electric-field dependence of photocarrier properties in the steady-state photocarrier grating experiment

We apply an experimental variation of the steady-state photocarrier grating technique by monitoring the photoresponse at higher electric fields and thus changing from diffusion to drift determined transport. Evaluation of the field-dependent experimental data is achieved with the analysis by Abel et al. [C.-D. Abel, G.H. Bauer and W. Bloss, Philos. Mag. B 72, 551 (1995)]. We study the photoelectronic properties of microcrystalline silicon samples and deduce the minority carrier diffusion length. From the variation in electric field the trapped charge density, responsible for charge neutrality under illumination, can also be determined. Thus additional information is gained which can be related to the density of states in the material.