S. A. CrippsT. J. C. HoseaA. KrierV. SmirnovP. J. BattyQ. D. ZhuangP. W. LiuG. TsaiHAO-HSIUNG LIN2018-09-102018-09-102008-09https://www.scopus.com/inward/record.uri?eid=2-s2.0-50649102823&doi=10.1016%2fj.tsf.2008.04.012&partnerID=40&md5=72541373d8bb6a3d709ec0d7f0d697ebIn narrow-gap semiconductors, non-radiative Auger recombination losses (via conduction, heavy-hole, spin split-off hole, heavy-hole processes) are sensitive to how the band gap energy, E0, compares to the spin-orbit splitting, Δ0. However, narrow-gap band structures have often not been very well characterised. We report on the mid-infrared photo-modulated reflectance of E0 and E0 + Δ0 transitions in high-quality, InAs-rich InAsSb and GaInAsPSb samples as functions of both temperature (T = 10-300 K) and antimony content ≤ 22.5%, for wavelengths up to ~ 4.75 μm. The measured T-dependence of E0 is generally consistent with that accepted in the literature and we confirm that Δ0 is T-independent. As a function of Sb fraction, E0 is consistent with the positive bowing parameter of + 670 meV quoted in the literature. However, Δ0 does not exhibit the currently accepted positive bowing parameter of + 1170 meV: rather, a best fit to our data tentatively suggests a negative bowing of ~ - 165 meV. Due to the importance of Δ0 in predicting and interpreting the performance of InAsSb-based devices, this result is expected to have a significant impact. © 2008 Elsevier B.V. All rights reserved.Band structure; Mid-infrared; Narrow gap; Pentenary; Photoreflectance; Semiconductor; Spin-orbit splitting; TernaryEnergy gap; Metallic compounds; Spin dynamics; Auger recombination; Band structure; Band-gap energies; Mid-infrared; Narrow gap; Narrow-gap semiconductors; Non-radiative; Pentenary; Photoreflectance; Semiconductor; Spin orbits; Spin-orbit splitting; Ternary; Gallium alloysjournal article10.1016/j.tsf.2008.04.0122-s2.0-50649102823WOS:000260360700016