Enhanced thermoelectric properties and layered structure of Sb ₂Te₃ films induced by special (0 0 l) crystal plane

In this Letter, special (0 0 l) crystal plane and uniquely alternate stress field can favorably influence the carrier and phonon transport properties of layered films. The oriented p-Sb₂Te₃ layered films have been successfully fabricated by the simple magnetron co-sputtering method. The measurement results show that the layered Sb₂Te₃ films with each layer ∼40 nm are (0 0 l)-preferential orientation. The highly (0 0 l)-oriented Sb₂Te₃ layered film with a thermoelectric dimensionless figure-of-merit ZT = 1.22 was obtained at room temperature. Introduction of such preferential (0 0 l) crystal plane and uniquely alternate stress field into TE films is therefore a very promising approach.