Effects of gamma-ray irradiation on the microstructural and luminescent properties of radio-frequency-magnetron-sputtered GaN thin films

The microstructural and luminescent properties of sputtered GaN thin films pre-irradiated and gamma-ray irradiated were systematically investigated. Analytical results revealed that the increasing dose of gamma-rays could enhance the more occurrence of nitrogen vacancies which not only created a prominent deep level luminescence but also destroyed the crystallinity of GaN thin films. For low dose of gamma-ray irradiation ( 4 Mrad (GaN)), evidence showed that by raising the irradiation dose, more associated Ga-H complexes will be effectively promoted, yielding an enhanced yellow band emission. However, for high dose of gamma-ray irradiation ( 4 Mrad (GaN)), further higher dose of gamma-rays could lead the dissociation of Ga-H complexes in GaN samples, resulting in a repressed yellow band emission.