Dominant intrinsic-exciton related luminescence from ZnSe grown by molecular beam epitaxy

Abstract

ZnSe layers were grown by molecular beam epitaxy onto (100) oriented GaAs substrates using various incident Zn/Se flux ratios. Substrate temperatures were varied over the range 300–400 °C while the layer growth rate was maintained at about 0.1 μm/h. 4.2-K photoluminescence (PL) spectra were recorded from 0.5-μm-thick ZnSe layers using the 365-nm line from a Hg(Xe) lamp (25-mW/cm2 power density). ZnSe layers which are judged to have been grown under near-stoichiometric growth conditions exhibited dominant intrinsic-exciton related luminescence. A narrow peak at 2.8008 eV dominated the 4.2-K PL spectra obtained from these layers. In addition, we also observed two unreported peaks in the ZnSe excitonic range which we term X at 2.8061 eV and Y at 2.8050 eV. These peaks are as yet unassigned.