Fig. 4: The electrical properties of P- and N-type Bi2Te3-based films.

The temperature-dependent electrical properities including Seebeck coefficient (a), resitivity (b), power factor (c) and mobility (d) for P-type Bi0.4Sb1.6Te3+x and N-type Bi2Te3+x (x = 0 and 0.17) films; The room temperature hall carrier concentration-dependent Seebeck coefficient (e), power factor (f) for P-type Bi0.4Sb1.6Te3+x and N-type Bi2Te3+x (0 ≤ x ≤ 0.24) films in this work, with a comparison to those of reported bulk materials17,18,19,20,42.