Creation of metastable defects in a-Si:H by keV-electron irradiation at different temperatures

Abstract The creation of metastable defects in a-Si:H films by 20 keV-electron irradiation at different degradation temperatures, T deg , is investigated. At low degradation temperature ( T deg = −170°C) no significant difference in the defect creation kinetics compared to that at room temperature is observed. This result indicates that the defect creation mechanism is not thermally activated. At higher degradation temperatures ( T deg = 50−100°C) the defect creation kinetics is strongly dependent on temperature, T deg , and electron intensity, I el , due to an increasing influence of thermal annealing during degradation. To explain these effects quantitatively an expression for the defect creation kinetics is derived based on a model assuming different kinds of defects with different annealing behaviour. Moreover, the resulting fit parameters give further information for the understanding of the multi-valued relation between photoconductivity, σ ph , and defect density, N D , observed for different degradation states.