Heteroepitaxial Growth of ZnS_xSe_1-x on GaAs_0.6P_0.4/GaAs by Metalorganic Vapor Phase Epitaxy

Tellurium-doped n-type GaAs0.6P0.4 /GaAs with a carrier concentration of 10(17) cm(-3) was used as the substrate for the heteroepitaxial growth of ZnSxSe1-x by metalorganic vapor phase epitaxy. The mirror-like surface morphology of lattice-matched ZnS0.47Se0.53 on GaAS(0.6)P(0.4) /GaAs was obtained. The hillock density increased with x deviating from 0.47. ZnS0.47Se0.53 lattice-matched to a GaAS(0.6)P(0.4)/GaAs substrate showed a strong peak with a full width at half maximum (FWHM) of 28 meV. The emission centered at 490 nm seemed to be favored at high Se/Zn ratios. This was considered to be associated with the Zn vacancy.