Refractive indices of ZnMgSSe alloys lattice matched to GaAs

Abstract

We have experimentally investigated refractive indices n of ZnxMg1−xSySe1−y, using the ellipsometry method and reflection-spectrum measurement. The samples are epitaxial films of undoped ZnxMg1−xSySe1−y grown by molecular beam epitaxy on semi-insulating GaAs substrates. The obtained dispersion relations of n in the transparent region are classified by the band-gap energy Eg. We have found that the refractive index n of ZnxMg1−xSySe1−y decreases as Eg increases. These results will be available for the design of blue laser diodes containing ZnMgSSe.