The structure of amorphous hydrogenated silicon and its alloys: A review

Abstract

The atomic structure of hydrogenated amorphous silicon is discussed from the point of view of three length scales, related to short-, medium- and long-range structure, and also from the viewpoint of Si-related, H-related and dopant-related environments. The results of the use of various techniques such as extended X-ray absorption fine structure, nuclear magnetic resonance and vibrational spectroscopy are discussed. The use of such chemically-specific structural probes has allowed information to be obtained for the first time on the local structural environments of the incorporated hydrogen and dopant atoms, and it is this structure which is crucial in controlling the electronic properties of this material.