Study of Amorphous Hydrogenated Silicon Nitrogen Alloys for Photovoltaic Applications

Amorphous hydrogenated silicon nitrogen alloys (a-Si1-xNx:H), with energy gap in the range 1.9-2.7 eV, were deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) using silane and ammonia gas mixture. The film structure and composition, as well as the neutral defect content and electrical behaviour were measured. A comparison with high quality a-SiC1-xCx:H films, deposited with the same PECVD system, is also reported. A good quality material, with photoconductive gain of about 105, and thus suitable for photovoltaic applications, can be obtained with a higher deposition rate with respect to a-SiC1-xCx:H films having the same energy gap.