Floating bonds and gap states in a-Si and a-Si:H from first principles calculations

Abstract

We study in detail by means of ab-initio pseudopotential calculations the electronic structure of five-fold coordinated (T_5) defects in a-Si and a-Si:H, also during their formation and their evolution upon hydrogenation. The atom-projected densities of states (DOS) and an accurate analysis of the valence charge distribution clearly indicate the fundamental contribution of T_5 defects in originating gap states through their nearest neighbors. The interaction with hydrogen can reduce the DOS in the gap annihilating T_5 defects.

To appear in Europhysics Lett

References in corpus (1)

• Analysis of atomic-orbital basis sets from the projection of plane-wave results

Cited by in corpus (4)

• Thermodynamic Behavior of a Model Covalent Material Described by the Environment-Dependent Interatomic Potential
• Sample dependence of the structural, vibrational, and electronic properties of a-Si:H: A density-functional-based tight-binding study
• Role of defects in the electronic properties of amorphous/crystalline Si interface
• Analysis of single and composite structural defects in pure amorphous silicon: a first-principles study