Effect of VI/II ratio upon photoluminescence properties of aluminum-doped ZnTe layers grown by MOVPE

The photoluminescence properties of aluminum (Al)-doped ZnTe layers grown by atmospheric pressure metalorganic vapor phase epitaxy have been investigated as a function of the ratio of transport rate of diethyltelluride and dimethyl (VI/II ratio). When VI/II ratio is increased, the excitonic emission and donor±acceptor pair emission due to Al donor become predominantly in the spectrum of ZnTe layer. This suggests that Al is effectively incorporated into ZnTe. Several bound excitonic emissions associated with residual acceptor impurities are also detected in the spectrum together with free excitonic emission. When VI/II ratio exceeds 3, the deep level emission associated with the complex of Al donor and Zn vacancy which roles the acceptor for ZnTe are induced. It seems that the intensity of this emission band is independent of dopant transport rate. # 2001 Elsevier Science B.V. All rights reserved