High thermoelectric power factors in sputter-deposited polycrystalline n-type BaSi2 films

Abstract

We formed n-type polycrystalline semiconducting BaSi2 films on insulating silicon nitride films by sputtering and investigated their electrical and thermoelectric properties. The electron concentration of the grown films was approximately 1015–1016 cm−3 at room temperature, and the electron mobility was higher than 103 cm2 V−1 s−1 despite the polycrystalline films being randomly oriented. The films contained a large concentration of oxygen (1.5 × 1021 cm−3). A large thermoelectric power factor of 386 μW m−1 K−2 was obtained at 309 K for B-doped n-BaSi2 films. This value is approximately 8.6 times higher than the previous highest power factor reported for n-BaSi2.