Thermoelectric properties of rf-sputtered CoSb₃ thin films on GaAs(100) substrate

Abstract

The thin film growth of CoSb₃ on a GaAs(100) substrate (the resistivity: 10⁷Ωcm) was made by using magnetron rf-sputtering, and the electrical and thermoelectric properties of the films were studied with relation to annealing temperature and film thickness. Polycrystalline films with the skutterudite structure were successfully grown on the GaAs (100) substrate. The obtained films were found to be p-type, and their hole mobility, electrical conductivity, and Seebeck coefficient depended significantly on the annealing temperature and the thickness. The Seebeck coefficient of 600μV/K, which is about three times as large as that for a p-type single crystal, was obtained for the thin film annealed at 750°C with thickness of 71nm, and the power factor reached about 2×10^-4 Wcm^-1K^-2.