A close relationship was found between the blue and yellow luminescence bands in n-type GaN films, which were grown without intentional acceptor doping. The intensity ratio of blue luminescence to yellow luminescence (IBL/IYL) decreased with the increase in edge dislocation densities as demonstrated by the (102) full-width at half-maximum of X-ray diffraction. In addition, the IBL/IYL ratio decreased with the increase in Si doping. It was suggested that the edge dislocation and Si impurity played important roles in linking the blue and yellow luminescence.

Role of Edge Dislocation and Si Impurity in Linking the Blue Luminescence and Yellow Luminescence in n-Type GaN Films. D.G.Zhao, D.S.Jiang, J.J.Zhu, Z.S.Liu, H.Wang, S.M.Zhang, Y.T.Wang, H.Yang: Applied Physics Letters, 2009, 95[4], 041901