Midinfrared photoreflectance study of InAs-rich InAsSb and GaInAsPSb indicating negligible bowing for the spin orbit splitting energy

The authors report on midinfrared photoreflectance measurements of the band gap (E0) and spin-orbit splitting energies (Δ0) in InAs-rich InAsSb and GaInAsPSb samples for varying antimony contents ⩽22.5%. The E0 behavior as a function of Sb content is consistent with the literature value bowing parameter of ∼670meV. However, Δ0 does not exhibit the positive bowing of +1170meV quoted in the literature: rather, a best fit to their data tentatively suggests a negative bowing of −225meV. This result is likely to have strong impact due to the importance of the Δ0 parameter in governing InAsSb-based device performance.