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 the electrical and thermoelectric properties of the films. The electron concentration of the grown films was mostly in the order of 1015-1016 cm−3 at 300 K, and the electron mobility was higher than 103 cm2 V-1 s-1 despite randomly oriented polycrystalline films. The grown films contained a large number 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 the B-doped n-BaSi2 films. This value is about 8.6 times higher than the previous highest power factor reported for n-BaSi2.