IMPURITY LEVELS OF ALKALINE-METALS IN ZINCSELENIDE SINGLE-CRYSTALS EXAMINED BY PHOTOLUMINESCENCE

Zincselenide (ZnSe) single crystals doped with alkaline metals (Li, Na , K, Rb and Cs) were grown by sublimation method. In order to obtain t he impurity levels of alkaline metals in ZnSe, we measured the tempera ture as well as excitation intensity dependences of the photoluminesce nce spectra. To further verify our results, we also measured the selec tive photoluminecence spectra of the aforementioned doped ZnSe. The va lues of the acceptor binding energy (E(A)) of Li, Na, K, Rb and Cs wer e 118 +/- 2, 98 +/- 2, 94 +/- 2, 89 +/- 2 and 74 +/- 2 meV, respective ly. The acceptor binding energy level is found to increase as the atom ic number of the dopant decreases.