PHOTOLUMINESCENCE OF LI-DOPED ZNSE SINGLE-CRYSTALS

Lithium was incorporated into high purity ZnSe single crystals by dipping the crystal into molten Se-0.1 at% Li alloy at 673 K. The I1Li line and two types of donor-acceptor pair (DAP) emissions (Q and R series) are observed. The acceptor binding energy of 105 meV is obtained for Li(Zn) from the results of the excitation intensity dependence of the peak energy of DAP emissions. Comparison with the previous results of Na-doped crystals reveals that the R series is attributed to Li(i)-Li(Zn) pairs and the Q series both to Ga(Zn)-Li(Zn) and to Na(i)-Na(Zn) pairs. The donor binding energies for Li(i) and Na(i) are estimated to be 15 +/- 1 and 16 +/- 1 meV, respectively.