Electronic consequences of the mutual presence of thermal and structural disorder

We investigate the simultaneous presence of topological and thermal disorder in amorphous silicon. We find that localized electronic states are very sensitive to moderate amounts of thermal disorder: for a given gap or band tail electronic eigenstate, both the fraction of the total charge on a given site as well as the energy eigenvalue can vary greatly with small ~thermally accessible! changes to the positions of the atoms. This observation, which is almost certainly relevant to any disordered insulator including glasses, has important implications to the microscopic theory of transport, optical properties, and doping, as well as existing models of defect kinetics. @S0163-1829~99!50426-8#