Growth studies on AlPSb, GaPSb new ternary III-V compounds for InP-based surface emitting lasers

The present paper describes studies of the growth of the AlPSb/GaPSb material system using gas source molecular beam epitaxy (GSMBE). The most remarkable feature revealed in this study is that alloy compositions strongly depend on group V supply ratio and growth temperature. We also investigated the optical and electrical properties of GaPSb. 20 pairs of AlPSb/GaPSb DBR reflectivity measurement demonstrates a stop-band width of 206 nn with maximum reflectivity exceeding 99% at approximately 1.66 μm. We demonstrated that an AlPSb/GaPSb system has a large index difference, which is useful for Bragg reflectors in InP based VCSELs emitting near 1.55 μm. The alloy composition of AlPSb is sensitive to the group V supply ratio, and that of GaPSb is sensitive to growth temperature. Precise control of growth conditions is therefore necessary with this material system. A highly reflective DBR was obtained in this growth study, its reflectivity near 1.6 μm exceeded 99%. The possibility of doping control in GaPSb layers was also demonstrated. This thin DBR structure will be of great help in creating a low-threshold VCSEL for use at long wavelengths