Structure and Thermoelectric Characterization of p-Type SnTe Nanobulk Material Synthesized by Charge Compensation Chemical Reaction

• Published in: Energies (Basel) Vol. 17; no. 1; p. 190
• Main Authors: Fujiwara, Ryosuke, Ikeda, Yuta, Kawaguchi, Takuto, Takashima, Yohei, Tsuruoka, Takaaki, Akamatsu, Kensuke
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.01.2024
• Subjects: chemical precipitation; Chemical synthesis; Electric properties; Electrical conductivity; Engineering; Grain boundaries; Graphite; Heat conductivity; low lattice thermal conductivity; Morphology; Nanocrystals; Plasma sintering; Scanning electron microscopy; Spectrum analysis; thermoelectric material; tin telluride; Toxicity; Japan
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en17010190

SnTe is the most widely studied p-type thermoelectric (TE) alternative to PbTe. In this study, we prepared a nanostructured SnTe bulk material via spark plasma sintering from a precursor synthesized by a chemical precipitation process without using organic molecules. The sintered sample comprised tiny grains (100–300 nm) with high-density grain boundaries. Eventually, because the material would contain no impurities acting as scattering nodes of charge carriers, the material exhibited a relatively high electrical conductivity of 7.07 × 105 Sm−1 at 310 K. The material demonstrated low lattice thermal conductivity (0.87 Wm−1K−1 at 764 K), which can be owing to the increasing phonon scattering at grain boundaries. The maximum ZT was 0.31 at 764 K in the measured temperature range. This study provides a method for the design of phase-pure and surfactant-free SnTe thermoelectric materials that exhibit low lattice thermal conductivity and high carrier mobility using a chemical synthetic approach.