Effect of antimony concentration on structural and transport properties of (Bi1-xSbx)2Te3 mixed crystal

Polycrystalline (Bi1-xSbx)2Te3 (0.60≤x≤0.68) alloys have been synthesized by solid state reaction method. Structural characterizations have been done using X-Ray Diffraction (XRD). Lattice parameter decreases with antimony (Sb) concentration. Sb doping leads to the modification in band structure and Fermi surface geometry. Band gap calculated from thermal variation of resistivity (ρ-T) data, decreases with Sb concentration. Sb concentration dependent power factor near room temperature have been calculated from obtained resistivity and thermopower data. Highest power factor obtained for (Bi0.40Sb0.60)2Te3 alloy.