Influence of Irradiation by High-Energy Protons on GaN Detectors

We had investigated effects of the irradiation by 24 GeV protons with doses ranging from $1×10^{14}$ up to $1×10^{16} p//cm^2$ on the properties of GaN ionising radiation detectors. In theγ-spectra of the samples radiation of $\text{}^7Be,$ $\text{}^{22}Na,$ and other long-lived radionuclides with A <70 was identified. Their activities were proportional to the irradiation dozes. Device contact properties were analysed by current-voltage I-V dependences. Created defects were revealed by the thermally stimulated defect 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 doses 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.