Leakage current studies of thick a-Si:H detectors under high electric field conditions

The leakage current of thick (up to 20 μm) a-Si:H p-i-n diodes developed for nuclear radiation detection were investigated. Performing current-voltage measurements at different temperatures and over a large electric field domain (up to 106 V/cm), different leakage current mechanisms, such as electron injection and field enhanced thermal generation, have been identified. The influence of the p layer thickness on the electronic injection was clearly demonstrated by means of spectral response experiments. The effect of a device forming procedure on the leakage current and on the noise power spectra of the devices has also been studied.