High Seebeck coefficient in PVD-WS<sub>2</sub> film with grain size enlargement
Takuya Hamada, Masaya Hamada, Taiga Horiguchi, Iriya Muneta, Kuniyuki Kakushima, Kazuo Tsutsui, Tetsuya Tatsumi, Shigetaka Tomiya, Hitoshi Wakabayashi
Abstract
Abstract A high Seebeck coefficient of 1.17 × 10 3 μ V K −1 was achieved using an on-chip thermoelectric device for a WS 2 atomic-layer film, which was synthesized by ultra-high vacuum RF magnetron sputtering as a function of sputtering power. A layered structure in parallel to the SiO 2 /Si substrate was confirmed from the transmission electron microscopy and X-ray diffraction spectra. The grain size and peak intensities of the Raman spectra increase with a decrease in the sputtering power. Accordingly, the resistivity and activation energy also increase. The WS 2 film can be used in thermoelectric generators, such as energy harvesters in LSIs and wearable devices.