The authors report on midinfrared photoreflectance measurements of the band gap (E0) and spin-orbit splitting energies (0) 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 ~670 meV. However, 0 does not exhibit the positive bowing of +1170 meV quoted in the literature: rather, a best fit to their data tentatively suggests a negative bowing of −225 meV. This result is likely to have strong impact due to the importance of the 0 parameter in governing InAsSb-based device performance.
Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 92 (17), 2008 and may be found at http://link.aip.org/link/?APPLAB/90/172106/1.