Study on proton irradiation effect of GaN optical and electrical properties

In-situ spectra of GaN material during proton irradiation and the influence of proton energy, fluence and temperature are obtained by the measurement of ion beam-induced luminescence (IBIL). The results show that the main luminescence peak comes from the radiation recombination from shallow donors to deep acceptors. The near-band emission was observed at low temperature, and the intensity presents a single decrease with fluence. When the temperature increases, the near-band emission appears red shift, while the yellow band appears blue shift. The depth distributions of protons in the material are different with different energies, resulting in variations of spectra due to the interface lattice mismatch and trace impurities. The capacitance–voltage curve and the output characteristic curve of GaN devices before and after irradiation were measured. It is found that the carrier density of the devices after 500 keV proton irradiation decreases more, and the degradation degree of low field mobility is more serious.