A study of light-induced degradation of a-Si:H by nanosecond laser pulse pairs of variable delay

Abstract Light-induced degradation of a-Si:H by intense nanosecond laser pulse pairs is studied to access the time scale of processes involved in dangling bond (DB) defect creation. The recombination kinetics accompanying DB creation is measured by transient photoconductivity and instant temperature. Based on the reduction of DB creation efficiency with the delay time between the pulses we suggest two successive time regimes. The first, decrease in DB creation efficiency at delays ⩽15 ns may be directly related to recombination, which initiates the structural transformation. The second, more gradual decrease in creation efficiency extending to microseconds is likely related to long-living DB defect precursors.