Anderson transition and thermal effects on electron states in amorphous silicon

TL;DR

This paper investigates how electron states in amorphous silicon transition from localized to extended and how thermal disorder influences these states, highlighting significant fluctuations and potential effects on doped or photo-excited systems.

Contribution

It introduces a realistic large-scale model for the Anderson transition in amorphous silicon and examines the impact of thermal effects on localized electron states.

Findings

Localized states fluctuate dramatically under thermal disorder

Thermal effects can significantly alter conjugate energy levels

Large-scale models effectively capture the Anderson transition in amorphous silicon

Abstract

I discuss the properties of electron states in amorphous Si based on large scale calculations with realistic several thousand atom models. A relatively simple model for the localized to extended (Anderson) transition is reviewed. Then, the effect of thermal disorder on localized electron states is considered. It is found that under readily accessible conditions, localized (midgap or band tail) states and their conjugate energies may fluctuate dramatically. The possible importance of non-adiabatic atomic dynamics to doped or photo-excited systems is briefly discussed.