SENSITIVITY MEASUREMENTS OF THICK AMORPHOUS-SILICON P-I-N NUCLEAR-DETECTORS

20 mu m thick p-i-n diodes were deposited at high rate using a PECVD p rocess. The p-i-n structures have been specifically tailored in order to sustain high reverse bias voltages and exhibit low leakage currents . Mean electric fields up to 5.10(5) V/cm have been applied to our dev ices. We report the electrical characterization of such devices in ter ms of I(V,T) curves. Different regimes have been identified and the ac tivation energy of the reverse current is deduced. A spectral analysis of the noise has been performed. Electronic transport of both electro ns and holes has been studied using a Time of Flight technique. Finall y, the detector response to alpha and beta particles, and X-rays has b een studied in order to measure the collection efficiencies of thick a -Si:H detectors.