Magneto-optic and magnetotransport study of InAs/Ga1-xInxSb superlattices

InAs/Ga 1-x In x Sb superlattices have been investigated by magneto-optical and magnetotransport techniques. Bandgaps, 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 to 12.4 mu m) 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 times larger than in HgCdTe (the industry-standard IR material). This is necessary for reduced dark currents and good optical absorption coefficients in this material. Finally, the first observation of higher-order electron and hole subbands (by interband magneto-optics) in this material system is reported.