Electrical properties of InAsxSb1−x alloys

Abstract

Measurements have been made of the high-temperature Hall coefficient, electrical conductivity, and thermoelectric power in polycrystalline n-type samples of InAsxSb1−x alloys of extrinsic carrier concentration ~1017/cm3. From the Hall-coefficient data, values of the extrapolated absolute-zero band gap E00 have been determined over the whole alloy range, the thermoelectric power results being used to provide a correction factor to allow for effects of degeneracy. In all cases this correction was found to be very small. The resultant values of E00 for the alloys are somewhat lower than those obtained previously from optical absorption data and show a minimum of 0.17 eV at x ~0.4. From the electrical conductivity data, values of electron mobility μc have been obtained as a function of temperature T and composition x. At all temperatures in the range 0–500 °C, μc is found to vary linearly with x, indicating that the effects of alloy scattering are negligible. For each value of x, μc is found to satisfy the relation μc = μ0 exp (−T/θ), and the variation of θ with x has been determined.