James M. Markovics

Metastable photoenhanced thermal generation in a‐SeTe alloys

The mechanism of isothermal bulk carrier generation in the dark and the sensitizing effects of prior penetrating illumination and thermal history have been investigated in a composition series of a‐Se:Te alloy films using xerographic techniques. In all cases, thermal generation is characterized by the simultaneous production of free holes and deeply trapped negative space charge. Results suggest that dark carrier generation is controlled by deep native (thermodynamic) defect centers whose population at a given temperature below Tg can be temporarily altered by photo and/or thermal excitation.

Dispersive thermal carrier generation in amorphous SeTe alloys

The dark decay of open circuit surface voltage on a series of capacity charged amorphous Se:Te films is analyzed. It is demonstrated that dark decay is controlled by thermal emission from discrete states deep in the mobility gap. The rate of dark decay and the shape of the dark decay function dV/dt vs t vary with alloy composition. This composition induced variation in the thermal emission process is demonstrated to exhibit experimental features analogous to those which characterize dispersive transport.