Toward enhancing the thermoelectric performance of PLD-grown single and bilayer Bi₂Te₃ and Sb₂Te₃ thin films

The dual nature of thermoelectric materials leads scientific community for extensive research towards this direction. In present study, we developed the nanostructured thin films of single and bilayer of Bi₂Te₃ and Sb₂Te₃ via pulse laser deposition technique on silicon substrates. The influence of film structure, morphologies and chemical composition on the thermoelectric properties were investigated in detail using XRD, SEM, AFM, FESEM and Quantum design PPMS. All the samples were found to be polycrystalline in nature with preferred (015) orientation and a highly stable rhombohedral phase. The bilayer p-type Bi₂Te₃/Sb₂Te₃ thin film system shows a variation in electrical resistivity from 13.5 × 10⁻³Ω.cm to 1.5 × 10⁻³Ω.cm and Seebeck coefficient up to 225 µV/K. Therefore, this work demonstrates a modest procedure to enhance the thermoelectric performance of Bi₂Te₃ and Sb₂Te₃ thin films by creating their hybrid nano-structure at a particular temperature without inflicting any damage of the sample.