Photoluminescence measurements were used to investigate the dependence of the optical properties of p-type CdTe and p-type Cd0.96Zn0.04Te 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, AX, peak at 1.588eV in p-type CdTe was resolved into an exciton that was bound to a neutral donor, DX, peak at 1.592eV and an AX 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 DX 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. The intensity of AX at 1.609eV in the p-type CdZnTe changed slightly as a function of the Br concentration. The intensities of the luminescence peaks, which were due to the recombination of electrons (in the conduction band) with acceptors, did not vary. The results suggested that the number of Cd vacancies could be reduced by the addition of Zn.

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