COMPOSITION DEPENDENCE OF PHOTOLUMINESCENCE SPECTRA IN ZN1-XMGXSE MIXED-CRYSTALS

Zn1-xMgxSe mixed crystals with (x) ranging from 0 to 0.56 were obtaine d by high pressure Bridgman method. It has been found that a phase tra nsition from sphalerite structure to wurtzite one occurs at x = 0.185 +/- 0.03. The crystals exhibit blue-violet and yellow-green (depending on x) luminescence in the temperature range from 40 K to room tempera ture. An attempt has been also made to dope Zn1-xMgxSe crystals with A l. The incorporation of Al produces a strong green photoluminescence i n the temperature range from 40 K to 300 K but almost completely quenc hes the near-band-edge emission.