THEORETICAL STUDIES OF ELECTRONIC STATES PRODUCED BY HYDROGENATION OF AMORPHOUS SILICON

First-principles calculations of electronic energies of hydrogenated amorphous silicon have been performed for a series of realistic structural models in which hydrogen appears as SiH, SiH2, SiH3, (SiH2)2, and SiHHSi (a broken Si-Si with two H atoms). Whereas all these models are consistent with photoemission experiment (less so for SiH3), only the last two are found to give band-gap states. The broken-band model is in good agreement with several sets of experiments. © 1979 The American Physical Society.