Sensitivity measurements of thick amorphous-silicon p-i-n nuclear detectors

20 μm thick p-i-n diodes were deposited at high rate using a PECVD process. 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 5.105 V/cm have been applied to our devices. We report the electrical characterization of such devices in terms of I(V,T) curves. Different regimes have been identified and the activation energy of the reverse current is deduced. A spectral analysis of the noise has been performed. Electronic transport of both electrons and holes has been studied using a time of flight technique. Finally, the detector response to alpha and beta particles, and X-rays has been studied in order to measure the collection efficiencies of thick a-Si:H detectors