DONOR-ACCEPTOR PAIR BANDS IN ZNSE

The donor-acceptor pair (DAP) bands have been studied in single crystals of ZnSe grown by vapor-phase epitaxy, from solutions of Ga, and In, and also by liquid-phase epitaxy. The temperature dependence of both steady-state photoluminescence and time-resolved spectra was used to identify the DAP bands R0, Q0, P0 associated with Li and Na dopants. The DAP band Q0 at 2.695 eV was already identified by Merz et al. as due to AlZn+-LiZn-. We have associated the DAP band P0 due to transitions involving AlZn+ donor and NaZn- acceptor and the DAP band R0 due to transitions involving a shallow donor and LiZn- acceptor, respectively. This shallow donor level seems to be associated with the presence of Li in ZnSe and could be Liint+. From these studies we obtain the acceptor level due to NaZn, 124±2 meV, and the shallow donor associated with Liint as 26 meV, respectively. This study suggests that compensation in ZnSe may be related to background donor impurities such as Liint rather than native defects. © 1979 The American Physical Society.