[2P01-29] Poster session

[2P29] Synthesis and Thermoelectric Properties of WTe₂ and Se-Doped WTe_2-xSe_x Nanowires from W₁₈O₄₉ Precursors

*Hiroki Waizumi¹, Wataru Ise¹, Zhefan Gao¹, Seiya Yokokura¹, Ryo Abe², Masakazu Nakamura², Toshihiro Shimada¹ (1. Hokkaido University (Japan), 2. Nara Institute of Science and Technology (Japan))

W₁₈O₄₉ nanowires were used as one-dimensional precursors for the synthesis of WTe₂ and Se-doped WTe_2-xSe_x nanowires. W₁₈O₄₉ was prepared solvothermally from WCl₆ in ethanol, then reacted with elemental Te or Te/Se and NaBH₄ in evacuated quartz tubes at 450℃. XRD, Raman spectroscopy, SEM–EDS, TEM, and ICP–OES confirmed the formation of nanocrystalline products and retention of nanowire morphology. Se substitution induced partial structural modification toward a 1T′-related configuration. TEM revealed layered nanowires with diameters of about 25 nm and a lattice spacing of approximately 0.7 nm. Both products showed p-type conduction. Compared with WTe₂ powder, the nanowires exhibited higher Seebeck coefficients, lower thermal conductivity, a power factor nearly two orders of magnitude higher, and ZT values exceeding reported bulk polycrystalline Td-WTe₂. Further carrier optimization is required.

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