High thermoelectric performance of rapidly microwave-synthesized Sn1−δS

Abstract

Phase-pure polycrystalline Sn_1−δS has been prepared using a one-step microwave-hydrothermal procedure. Its structural characterization by neutron powder diffraction and transmission electron microscopy shows an orthorhombic Pnma phase at room temperature with the presence of a significant amount of Sn vacancies (Sn_0.87S), randomly located in the crystal structure. This work proves that this inexpensive 2D material, constituted by high abundance elements, is a promising candidate for thermoelectric applications. This is confirmed by its relatively high carrier density and good mobility (2.5 × 10¹⁸ cm⁻³ and 13 cm² V⁻¹ s⁻¹ at room temperature, respectively) found in the microwave-hydrothermal-synthesized sample, which favours high thermoelectric performance. In addition, a remarkably high Seebeck coefficient (682 μV K⁻¹) combined with low electrical resistivity (5.6 × 10⁻⁴ Ω m) and thermal conductivity (0.57 W m⁻¹ K⁻¹) at 523 K produces a reasonably high figure of merit ZT of 0.76.