Some electrical and optical properties of evaporated a-Si: H doped with molecular hydrogen

Electron-gun evaporated a-Si has been doped with large amounts (up to 12 at.%) of molecular hydrogen with no external dissociation facilities required. The infrared transmission spectra taken from these films show a sole peak in the Si—H x stretching region at 2085 cm−1, indicating a bonding type hitherto associated with SiH2-type grouping. The room-temperature electrical conductivity exhibits a remarkable decrease of six orders of magnitude from 10−4 to 10−10 (Ω cm)−1 on annealing and is thermally activated above 100°C with an activation energy of 0·7 eV.