Possibilities of CdTe-based X/γ-ray detectors with MoO x contacts

Transport properties of the CdTe X/γ-ray detectors prepared by the deposition of molybdenum oxide thin films by DC reactive magnetron sputtering onto semi-insulating p-type single-crystal CdTe were studied. Current-voltage characteristics of both detectors with two Ohmic contacts and barrier structure were investigated at different temperatures. The conduction mechanism in the MoOx/p-CdTe/MoOx heterojunction is dominated by generation-recombination in the space-charge region. The Schottky barrier height, concentration of uncompensated impurities and charge carrier lifetime were determined from the comparison of the experimental and calculated results. Finally, the spectra of the Am isotope measured by the detectors are presented. It is shown that the MoMoO x /p+/p-CdTe/p+/MoO x -Mo structures can be used as X/γ-ray detector in the spectrometric mode.