Thermoelectric properties of sputter deposited Bi2Te3-PbTe multilayer thin films

Pristine Bi2Te3, PbTe, and multilayer of Bi2Te3/PbTe thin films were deposited on a glass substrate using the DC magnetron sputtering technique. XRD, FE-SEM, AFM, Raman, electrical, and thermal properties were analyzed to understand the structural, surface, electrical resistivity, Seebeck coefficient, and electrical part of thermal conductivity of the films. The structural analysis by XRD confirms the phase purity of the pristine films and the mixed phase for the multilayer films. FE-SEM morphology images showed a significant variation in the surface structure. The Seebeck coefficient, resistivity, and power factor analysis were carried out to understand the charge transfer processes. Multilayer films exhibited a high absolute Seebeck coefficient (S) value of -140.6 mu V/ K for BPB-5 film and -130.6 mu V/K for BP -6 film compared to -92.9 mu V/K of Bi2Te3 film with n -type behavior at 370 K. Similarly; the power factor value is also higher for multi -layer films compared to pristine film.