(Bi2Te3)1−x(PANI)x compositions- synthesis, structural, spectroscopic characterization with enhanced thermoelectric performance

The coupling between semiconductor/ polymer compositions is one of the unique trials to attain outstanding nanocomposite thermoelectric materials. Herein, Bi 2 Te 3 /PANI composites prove their ability to achieve the physical properties of the thermoelectrics by the variation of stoichiometric concentrations. The in-situ polymerization method was utilized to obtain Bi 2 Te 3 /PANI compositions. The structural characteristics of the materials were investigated by X-ray diffraction (XRD). XRD, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) confirm the homogeneous growth of PANI over the surface of Bi 2 Te 3 nanoparticles, affect on the order structure with low crystallinity during the polymerization. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analyses illustrate the π-π interactions of uniform PANI on Bi 2 Te 3 nanoparticles. The other strong interactions, including electrostatic and hydrogen bonding between Bi 2 Te 3 and PANI may construct a route to enhance the order of the structure of the chains and improve the thermoelectric performance. Distinctive revolutionize the electrical resistivity, Seebeck Coefficient, and the power factor with increased PANI concentrations, which improves thermoelectric performance. The spin concentration charge carriers were determined from Electron Spin Resonance (ESR) dependent on the PANI doping levels. The formation of polarons and bi-polarons were produced during the doping process represent the carriers in these systems. • Bi 2 Te 3 /PANI nano-compositions were successfully achieved via the in-situ polymerization technique. • Structural, topographic, thermal properties were tested for Bi 2 Te 3 /PANI compositions. • The enhancement of thermoelectric performance and the power factor for Bi 2 Te 3 /PANI composites increased with PANI concentration. • ESR identified the formation of polarons and bi-polarons. • Polarons and bi-polarons were produced during PANI increase which enhances charge carriers in Bi 2 Te 3 /PANI systems.