Role of edge dislocation and Si impurity in linking the blue luminescence and yellow luminescence in n-type GaN films

A close relationship is found between the blue and yellow luminescence bands in n-type GaN films, which are grown without intentional acceptor doping. The intensity ratio of blue luminescence to yellow luminescence (I-BL/I-YL) decreases with the increase in edge dislocation densities as demonstrated by the (102) full width at half maximum of x-ray diffraction. In addition, the I-BL/I-YL ratio decreases with the increase in Si doping. It is suggested that the edge dislocation and Si impurity play important roles in linking the blue and yellow luminescence.

National Natural Science Foundation of China 60836003 60776047National Basic Research Program of China 2007CB936700 The authors acknowledge the support from the National Natural Science Foundation of China (Grant Nos. 60836003 and 60776047) and the National Basic Research Program of China (Grant No. 2007CB936700).