Origins of reverse bias leakage currents in hydrogenated amorphous silicon p-i-n detector structures

The transport-simulation computer program amps has been used to explore the origin and behavior of dark leakage currents in hydrogenated amorphous silicon p-i-n detector structures. A comparison of simulated and experimental data reveals that the experimentally observed voltage dependence of the reverse bias current-voltage characteristics can be explained by a varying defect density through the i layer, due either to dopant permeation or to Fermi-level-driven defect densities, as well as by the previously suggested field-enhanced generation. amps simulations indicate that the dependence of these reverse leakage currents on i-layer thickness would be useful in determining the relative importance of each possible mechanism.