Bi substitution effects on Sb₂Te₃ thin films

We have investigated the structural and thermoelectric properties of (Sb_1-xBi_x)₂Te₃ MBE grown thin films on CdTe(111). Analysis of X-ray diffraction patterns (θ-2θ scans and rocking curves) of the films shows that they are of high quality and that they are well aligned with their (00.l) axis normal to the substrates. Measurements of the temperature-dependent thermoelectric power of the films were performed with respect to the binary composition of Sb and Bi, x. For the samples in the range 0.2<x<0.3, the room temperature thermopower values are in the range 184-159 μV/K. Measurements of the temperature-dependent resistivity and Hall coefficient of the films were also performed. For the samples in the range 0.2<x<0.3, the room temperature carrier concentrations were 3.93-5.13×10¹⁹ cm^-3 and the mobilities were 24.6-64.0 cm²V^-1s^-1.