Abstract
The photoluminescence properties of a low-energy (0·9 eV) emission band are examined for a wide variety of samples of a-Si: H prepared in both glow-discharge and sputtering reactors, and are compared with those of similar bands seen in microcrystalline and crystalline silicon. We also report the first photoluminescence measurements on magnetron-sputtered films, which suggest that this material has defect densities as low as those found in good quality glow-discharge a-Si: H.