The effects of 248 nm KrF excimer laser irradiation on the properties of Mg-doped GaN film were investigated. The laser irradiation-induced property changes were studied by photoluminescence, I-V C-V, DLTS, AFM measurements. It was found that under appropriate laser conditions, 248 nm KrF excimer laser irradiation could significantly increase the PL intensity of Mg-doped GaN film. The electrical properties (hole concentration and conductivity) were also improved by laser irradiation. From DLTS results, the hole-trap level appeared to have been effectively eliminated by laser treatment. The process has potential applications in the fabrication of GaN-based electronic and opto-electronic devices. (c) 2005 Elsevier B.V. All rights reserved.