Effect of Low-Level Boron Doping on Transport Properties of a-Si:H and a-SiGe:H Alloys

Abstract
Large simultaneous changes in ambipolar diffusion length and d.c. photoconductivity are observed with boron doping below 5ppm. We show that the observation can be explained successfully with a model for the doping effect, which is also consistent with earlier studies. The μτ products for both carriers as a function of doping are determined. The light intensity dependence of diffusion length and photoconductivity is also discussed.