Abstract
Carbon was in situ doped into GaN during halide vapor phase epitaxy and photoluminescence properties of the C-doped GaN film were investigated. It has been found that incorporation of carbon into GaN produces a significant yellow luminescence around 2.2 eV. The peak position of the yellow band blueshifts linearly and the intensity of that band monotonically decreases with measurement temperature, with systematic changes in the linewidth. These results suggest that multiple donor–acceptor recombination channels are involved in the yellow luminescence.