Order and disorder in amorphous, tetrahedrally coordinated semiconductors A curved-space description

Abstract

This paper presents a new approach to the structure of amorphous semiconductors. Regular structures (‘polytopes') defined in three-dimensional curved space are used to describe an ideal order. We assume that disorder in real material is comparable to the disorder induced by the mapping of the polytope onto Euclidian space. This mapping has two effects: elastic distortions and internal cut surfaces. These surfaces can be relaxed by disclination lines. A systematic generation of amorphous Si: H structural models can be achieved by the saturation, with hydrogen atoms, of the dangling bonds arising near the defects.