DENSITY-OF-STATES AND PHOTOCONDUCTIVITY LIGHT DEGRADATION IN A-SI-H AT DIFFERENT TEMPERATURES

We have studied the light degradation process of a-Si:H at different t emperatures monitoring the defect density and the photoconductivity. O ur data are not in complete agreement with die predictions of the two most widely accepted models (the recombination induced bond breaking m odel and the stretched exponential one). We show that our experiments can be well interpreted by a model in which the creation rate is propo rtional to the square of the photoconductivity and in which the anneal ing rate is computed considering a distribution of energy barriers and it is enhanced by the degradation light.