Synergistic enhancement of thermoelectric performance in N type Bi2Te3 by incorporating CuO ceramic nanoparticles

Abstract

In the present work, copper oxide (CuO) ceramic nanoparticles (NPs) were embedded in a Bi₂Te₃, introducing an unexplored composition of ‘n’ type binary alloy, Bi₂Te₃ mixed with CuO Nps. Bi₂Te₃ powder was mechanically milled and mixed with CuO in three different weight percentages (1 %, 2 %, and 3 %). The synthesized nanocomposite powders were then hot-pressed at 200 °C to form pellets. X-ray diffraction (XRD) of the nanocomposite powder and compacted samples revealed no major change in the crystal structure of both composites. Scanning electron microscopy (SEM) revealed that CuO NPs were successfully embedded at grain boundaries of the Bi₂Te₃ matrix. The reduction in lattice thermal conductivity was attributed to strong phonon scattering across multiscale mean-free pathways, while increased low-energy electron filtering raised the Seebeck coefficient and reduced the electronic thermal conductivity. This synergistic effect between CuO and Bi₂Te₃ achieved the highest “figure of merit” 0.99 at 483 K for the 3 wt% Bi₂Te₃-CuO nanocomposite.