Point-defect complexes which were related to the yellow luminescence (2.2eV) produced in un-doped GaN by 30MeV electron irradiation were studied by using a photoluminescence method. The yellow luminescence intensity in 700C-annealed samples was about 5 times greater than that in un-irradiated materials; thus indicating that deep-level defects were created by electron irradiation and subsequent annealing. The yellow luminescence was associated with point-defect complexes which arose from the combination of irradiation-introduced Ga vacancies with residual donor impurities; driven by high-temperature annealing. The yellow luminescence was not annealed out by annealing at 1000C; thus demonstrating the thermal stability of artificially introduced defects.

A Point Defect Complex Related to the Yellow Luminescence in Electron Irradiated GaN. K.Kuriyama, H.Kondo, M.Okada: Solid State Communications, 2001, 119[10-11], 559-62