Time-of-flight photocurrents in expanding-thermal-plasma-deposited a-Si:H

Time-of-flight (TOF) photocurrent investigations of hydrogenated amorphous silicon (a-Si:H) layers produced by means of an expanding thermal plasma (ETP) reveal a hole drift mobility that is, for depositions near 450 °C, consistenly one order of magnitude higher than the corresponding mobility in standard PECVD samples. Electron drift mobilities and µt products do not show such differences. The electronic density of states contains a prominent band of deep traps and the materials show evidence for non-amorphous inclusions.