Electrical properties of InAs_xSb_1−x alloys

Abstract

Measurements have been made of the high-temperature Hall coefficient, electrical conductivity, and thermoelectric power in polycrystalline n-type samples of InAs x Sb 1−x alloys of extrinsic carrier concentration ~10 17 /cm 3 . From the Hall-coefficient data, values of the extrapolated absolute-zero band gap E 00 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 E 00 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 μ c have been obtained as a function of temperature T and composition x. At all temperatures in the range 0–500 °C, μ c is found to vary linearly with x, indicating that the effects of alloy scattering are negligible. For each value of x, μ c is found to satisfy the relation μ c = μ 0 exp (−T/θ), and the variation of θ with x has been determined.