A comprehensive and critical analysis was made of point defects in GaN, particularly their manifestation in luminescence, was presented. In addition to a comprehensive analysis of native point defects, the signatures of intentionally and unintentionally introduced impurities were addressed. The review considered in detail the characteristics and the origin of the major luminescence bands including the ultra-violet, blue, green, yellow, and red bands in undoped GaN. The effects of important group-II impurities, such as Zn and Mg on the photoluminescence of GaN, were treated in detail. Similarly, but to a lesser extent, the effects of other impurities, such as C, Si, H, O, Be, Mn, Cd, etc., on the luminescence properties of GaN were also reviewed. Further, atypical luminescence lines which were tentatively attributed to the surface and structural defects were considered. The effect of surfaces and surface preparation, particularly wet and dry etching, exposure to UV light in vacuum or controlled gas ambient, annealing, and ion implantation on the characteristics of the defect-related emissions was described.

Luminescence Properties of Defects in GaN. M.A.Reshchikov, H.Morkoç: Journal of Applied Physics, 2005, 97[6], 061301 (95pp)