The dependence of the structural and optical properties on the Te mole fraction in ZnS 1− xTe x/GaAs heterostructures

Abstract

Lattice-mismatched ZnS 1− x Te x epilayers with various Te mole fractions on GaAs (100) substrates were grown by double well temperature gradient vapor deposition. X-ray diffraction patterns showed that the grown ZnS 1− x Te x layers were epitaxial films. The photoluminescence spectra showed that the peak position of the acceptor-bound exciton (A 0, X) varied dramatically with changing the Te mole fraction and that the behavior of the (A 0, X) peak position of the ZnS 1− x Te x epilayers with a small amount of the Te mole fraction was attributed to a bowing effect. The reflectivity and ellipsometry spectra showed that the absorption energy peak was significantly affected due to the Stoke's effect. These results provide important information on the structural and optical properties of ZnS 1− x Te x /GaAs heterostructures for improving optoelectronic device efficiencies operating in the spectral range between near ultraviolet and visible regions.