Effects of the high-energy proton irradiation on the properties of GaN ionizing radiation detectors

Effects of the irradiation by 24 GeV protons on the properties of GaN ionizing radiation detectors were investigated. Irradiation dozes ranged from 1 x 1014 up to 1 x 1016 p/cm2. In the γ-spectra of the samples radiation of 7Be, 22Na and other long-living radionuclides with A<70 was identified. Their activities were proportional to the total irradiation doses. Device contact properties were analysed by IV dependencies. Created defects were revealed by the thermally stimulated spectroscopy. In the less irradiated samples the following values of the effective thermal activation energies were found: 0.12-0.16 eV, 0.18-0.22 eV, 0.35-0.42 eV and 0.84-0.94 eV. Meanwhile in the detectors irradiated with the highest dozes only current growth with the activation energy of about 0.8-1.0 eV could be identified. Effects of percolation transport in disordered media were proved in the irradiated material. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)