Photoluminescence measurements were used to investigate the dependence of the optical properties of p-type material upon the relative concentration of Br in a mixture of methanol and Br. It was found that, as the Br concentration was increased, the intensity of the luminescence increased. In addition, an exciton which was bound to a neutral acceptor, AX, peak at 1.588eV was resolved into an exciton that was bound to a neutral donor, DX, peak at 1.592eV and an AX peak. The mixed bands of the 1.574 and 1.546eV peaks were well-resolved by using a Br etchant concentration of 2%. In particular, the intensities of the DX and 1.574eV peaks increased by as much as 5 and 7 times, respectively. The intensity of the peak at 1.48eV, which was related to defects, also increased.

M.D.Kim, T.W.Kang, G.H.Kim, M.S.Han, H.D.Cho, J.M.Kim, Y.T.Jeoung, T.W.Kim: Journal of Applied Physics, 1993, 73[8], 4074-6