Tunnelling-assisted generation-recombination in pn a-Si junctions

A theoretical model is developed describing the trap-assisted tunnelling ca pture and emission mechanisms in amorphous silicon pn junctions. Adding the se transitions to a pure thermal capture-emission mechanism gives expressio ns for the nonequilibrium occupancy function. Integrating over all states i n the gap of an amorphous semiconductor, the equations for the generation-r ecombination rate are obtained, taking into account not only the thermal ca pture-emission process, but also the tunnelling transport of charge carrier s and the enhanced carrier transport due to the Poole-Frenkel effect. (C) 1 999 Elsevier Science Ltd. All rights reserved.