Time-resolved photoluminescence of cubic GaN grown by metalorganic vapor phase epitaxy

Time-resolved photoluminescence of high quality cubic GaN was measured to c larify the origin of the emissions observed in cubic GaN. The 3.27 eV emiss ion decay was fast and the intensity decreased with a lifetime of 260 ps at early decay and with a lifetime of 900 ps afterwards. The decay of the 3.1 8 eV emission was much slower than that of the 3.27 eV emission and the lif etime was 3.8 ns. In time-resolved spectra, the 3.18 eV emission had a broa dening on the high-energy side at early times and the peak moved to lower e nergies with increasing time. These results can be explained in terms of th e model for a donor-acceptor pair transition.