The kinetics of creation and annealing of light-induced metastable defects and their effect on photo-carrier lifetime were investigated in 2 good-quality hydrogenated amorphous Si samples using the constant photocurrent method and steady-state photoconductivity measurements at room temperature. Narrow distributions of annealing activation energies that peaked at about 1eV, account for the annealing of created metastable defects for both samples. A hysteresis-like relation was observed between light-induced defect density and photoconductivity. This relationship was different for the two samples investigated and also depends on light intensity used for degradation. Calculated distributions of annealing activation energies did not provide additional information in the explanation of the observed differences in the hysteresis-like relationship between the samples. Upon comparing the deduced annealing activation energies distributions with the one obtained by Zhang et al, it was concluded that more stable light-induced defects were created at longer illumination times or at higher light intensities, shifting the peak value of distribution of annealing activation energies from about 1 to 1.1eV.

Light-Induced Metastable Defect Formation and Annealing Kinetics in a-Si:H. A.O.Kodolbaş: Materials Science and Engineering B, 2002, 95[1], 67-72