Design of new UV/blue/green light emitters made of hexagonal-phase ZnMgCdOSSe mixed-crystal system fabricated on GaAs- and InP-(111) substrates

摘要

A new candidate for long lifetime short-wavelength light emitters made of hexagonal Ⅱ-Ⅵ compounds has been proposed. In this paper, the results of theoretical design of ZnMgCdOSSe-based light emitters fabricated on (111) plane of GaAs and InP substrates is presented. The band lineups of CdZnS/ZnSSe and CdZnS/ZnMgS structures were estimated with Harrison's LCAO theory. Further, as for the first step of an experimental investigation on the growth of high phase-quality hexagonal Ⅱ-Ⅵ compounds, growth of CdZnS epilayers were examined on GaAs(111) substrate. The epilayers were characterized by high-resolution X-ray diffraction reciprocal space and pole figure measurements. In this study, the optimum growth temperature was 300℃ for hexagonal phase CdZnS, and the inclusion of cubic phase CdZnS drastically decreased with increasing Cd content at 300℃.