Reduction of yellow and blue luminescence in Si-doped GaN by rapid thermal annealing

Si-doped GaN films grown by metal organic chemical vapour deposition have been annealed under different annealing conditions in N 2 ambient. The annealed films have been characterized by photoluminescence and high resolution X-ray diffraction. The results show that the rapid thermal annealing (RTA) treatment suppresses the yellow and blue luminescence bands in the annealed Si-doped GaN films. For the sample annealed at 850 °C for 3 min, the yellow and blue band intensities even decreases by approximate one order of magnitude over the as-grown sample. In addition, the densities of the edge and screw threading dislocations in the Si-doped GaN also decrease after the RTA treatment. These facts provide the evidence that the RTA technique can effectively improve the crystalline quality of the Si-GaN films.