MEASURED AND CALCULATED DISTRIBUTIONS OF DEEP DEFECT STATES IN HYDROGENATED AMORPHOUS-SILICON - VERIFICATION OF DEEP DEFECT RELAXATION DYNAMICS

The density of states in the upper half of the mobility gap of both intrinsic and n-type a-Si:H samples was determined by the modulated photocurrent (MPC) and junction capacitance methods. We conclude that the narrow defect band revealed by the MPC measurements reflects the distribution of relaxed D0 states, while the broader and deeper defect band obtained by capacitance measurements corresponds to relaxed D- states. Both distributions are correctly predicted by a calculation that takes into account the relaxation dynamics of deep defects in these different charge states.