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 N2 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.