Enhanced Thermoelectric Performance of CuInTe2 via SnTe Incorporation and Microwave Synthesis

Incorporating a secondary phase represents a promising strategy for enhancing the thermoelectric performance of materials. In this study, CuInTe2was modified with SnTe powders at various weight fractions (0, 0.5, 1, 2, 4 wt%) and subsequently synthesized via rapid microwave melting. The phase composition and microstructure of the resulting materials were systematically characterized. Structural analyses revealed that the introduction of SnTe induced the incorporation of Sn and Te into the CuInTe2lattice, accompanied by a progressive contraction in lattice parameters. Owing to the spontaneous formation of intrinsic Sn vacancies in SnTe and the regulation of carrier concentration, electrical conductivity of up to 2.7 × 104Sm−1was achieved, representing a 1.7-fold increase over pristine CuInTe2. Coupled with a notable reduction in lattice thermal conductivity (0.9 Wm−1K−1at 700 K), a maximum figure of merit of 0.44 was obtained for the CuInTe2-2 wt% SnTe sample. While the absolutezTvalue is moderate compared to state-of-the-art CuInTe2-based materials, this work establishes the feasibility of microwave melting combined with second-phase incorporation as a rapid and energy-efficient synthesis pathway for CuInTe2modification. These results demonstrate that the introduction of SnTe is a viable strategy for enhancing the thermoelectric performance of CuInTe2.