Thermal and Electrical Transport in InAs-GaAs Alloys

Abstract

The thermal conductivity, Seebeck coefficient, and electrical resistivity have been measured as a function of temperature for various impurity concentrations and alloy compositions. Room‐temperature measurements of Hall mobility and the optical determination of electron effective masses have been made. n‐type alloys between 50 and 70 mole % InAs, doped with selenium to give room‐temperature resistivities of 4 to 8×10⁻⁴Ω·cm, give an optimum figure of merit. The maximum figure of merit at 700°K was measured to be 0.98×10⁻³ deg⁻¹· p‐type alloys (30%–70% InAs) doped with zinc gave a maximum figure of merit of only 0.4×10⁻³ deg⁻¹ at 700°K. The room‐temperature Hall mobilities and Seebeck coefficients of the p‐type alloys are lower than might be anticipated. The electron effective masses were found to vary uniformly with composition.