Determination of band gap and effective masses in InAs/Ga1−xInxSb superlattices

InAs/Ga1−xInxSb superlattices have been investigated by magneto-optical and magnetotransport techniques. Band gaps, determined from interband magneto-optical measurements and from the temperature dependence of the intrinsic carrier concentration, are in the long wavelength infrared region (8.3–12.4 μm) and are in good agreement with gaps calculated from a two-band model. Both electron and hole effective masses were measured by cyclotron resonance and the electron effective mass is found to be a factor of 4–5 larger than in HgCdTe (the industry standard IR material). This is necessary for reduced dark currents and good optical absorption coefficients in this material.