DIELECTRIC RESPONSE AND ITS LIGHT-INDUCED CHANGE IN UNDOPED ALPHA-SI-H FILMS BELOW 13 MHZ

The low frequency (<13 MHz) dielectric response and its light-induced change in undoped a-Si:H were investigated in detail. The dielectric c onstant epsilon (the real part) in this range decreases with illuminat ion time: following a stretched exponential law similar to that found for other light-induced changes. The saturation relative change was ab out 0.1-0.2 % for the measured samples. The change is fading away eith er after repeated illumination-annealing training or by aging at room temperature. The present results indicate some rearrangement of the wh ole Si network caused by light soaking.