Optical properties of wide band-gap semiconductor ZnMgSTe have been investigated. ZnMgSTe thin film crystals were grown on GaAs substrates by molecular beam epitaxy. It was found that ZnMgSTe thin films exhibit relatively strong photoluminescence as compared to ZnSTe thin films. It was also found that the luminescence mechanism in ZnMgSTe is similar to that in ZnSTe and related to Te iso-electronic traps. The enhanced luminescence with Mg incorporation may be due to the fluctuation in microscopic composition of Zn and Mg.
