Epitaxial growth of ZnMgSSe on GaAs substrate by molecular beam epitaxy

We propose a new material, ZnMgSSe, as the cladding layer of a blue-light laser diode. Band-gap energy can be varied from 2.8 to near 4 eV, maintaining lattice-matching to a (100)GaAs substrate. The band-gap energies of MgS and MgSe (zincblende structure) are estimated to be about 4.5 eV and 3.6 eV, and the lattice constants are 5.62 Å and 5.89 Å, respectively. The refractive index of ZnMgSSe lattice-matched to GaAs is smaller than that of ZnSSe lattice-matched to GaAs. ZnMgSSe meets the requirements of the cladding layer of ZnSSe for fabricating the blue-light laser diode.