The picosecond time-resolved photoluminescence spectra of a high quality insulating wurtzite GaN semiconductor was investigated under a low excitation intensity at temperatures from 8.7 to 50 K. The sample was grown via metallorganic chemical vapor deposition (MOCVD) on a sapphire substrate at 76 Torr. Resolutions of transmission lines with peak positions at 3.503 and 3.512 eV were assigned to the band-to-band transitions of A- and B- valence bands, respectively. Least-squares fitting of data showed a PL decay with a lifetime of about 3.7 ns and the total impurity concentration was found to be smaller with the insulating sample.
|Number of pages||3|
|Journal||Applied Physics Letters|
|State||Published - Jun 21 1999|