Phosphorus Doping and Photoinduced Changes in Hydrogenated Amorphous Silicon-Carbon Alloy Films

Hydrogenated amorphous silicon carbon alloy films have been prepared by the RF glow discharge technique. The effect of phosphorus doping on the optoelectronic properties has been studied at different silane/methane flow compositions. The reduction of doping efficiency in wider-band-gap material has been attributed to increasing disorder with carbon incorporation. The spectral photoresponse data have been analysed to show that the effect is consistent with current models for doping in tetrahedral amorphous semiconductors. The light-induced changes in the properties have been explained in terms of the relative effects of phosphorus and/or carbon incorporation.