Control of Composition and Growth Rate of ZnMgS Grown on GaP by Molecular Beam Epitaxy Using Excess Sulfur Beam Pressure

Abstract

We have grown ZnMgS ternary alloys on (100) GaP substrates by molecular beam epitaxy. Using excess sulfur beam pressure evaporated from an elemental S source, we successfully controlled the alloy composition and the growth rate around the lattice-match condition to GaP substrates, which were not reproducible when the S beam was not used. From photoluminescence excitation spectra, it is observed that the band gap of Zn 0.80 Mg 0.20 S, which is lattice-matched to GaP, is 0.15 eV larger than that of ZnS.