Relaxation induced changes in electrical behavior of glassy chalcogenide semiconductors

Effects of structural relaxation and the glass‐transition process are clearly manifested in the electrical behavior of glassy‐chalcogenide films. Analysis of the transport and trapping of photoinjected carriers and of the thermal generation of free carriers in the bulk reveal that in chalcogenides each of these processes is mediated by a specific manifold of localized electronic states residing in the mobility (forbidden) gap. It is demonstrated that in the vicinity of T g the population of these states varies systematically with the structural state of the glassy film always tending toward a temperature‐dependent quasi‐equilibrium. The present‐observations thus clearly establish the structural origin of key electronic‐gap states and simultaneously reveal the mechanism by which relaxation impacts electrical behavior.