Thermal generation currents in hydrogenated amorphous silicon p-i-n structures

Dark conductivity in amorphous silicon p-i-n devices arising from thermal generation through bulk defect states is explored. The current decays slowly after a voltage is applied, due to depletion of charge from the undoped layer, and is voltage dependent due to a field-enhanced generation rate. Creation of metastable bulk defects by light soaking reversibly increases the current. The steady-state generation current is dervied from the measured relaxation time and depletion charge.