Rate equation for metastable defects in hydrogenated amorphous silicon: The form of the light-induced annealing term

Abstract

Experimental evidence for light-induced annealing of defects in a-Si:H has recently been reported. However the experimental data about the removal of the defects under illumination are so limited that considerable uncertainty remains about the form of the light-induced term in the defect rate equation and its thermal activation energy. We here analyze the kinetics of light-induced creation and annealing of metastable defects in terms of a dispersive model. Our analysis suggests that the light-induced annealing term is proportional to the product of defect density and the carrier density. The activation energy of the light-induced annealing prefactor is about 0.45 eV.