The photoluminescence of microwave-assisted chemical vapor deposited material was studied by using ultra-violet synchrotron radiation. The photoluminescence spectrum of the 5RL band (intrinsic defect), which could not be detected by using cathodoluminescence techniques, was determined for both undoped (as-grown) and B-doped (200ppm) samples. Defect formation in the thin near-surface layers was characterized. The B-related peak (2.3eV) was detected in B-doped material, while the A band (2.9eV) was not observed. After remote H-plasma treatment, the near-surface defect-related peak in the photoluminescence spectra disappeared.
J.Won, A.Hatta, T.Ito, T.Sasaki, A.Hiraki: Applied Physics Letters, 1996, 69[27], 4179-81