The Potential of Tellurene-Like Nanosheets as a Solution-Processed Room-Temperature Thermoelectric Material.

Low-dimensional thermoelectric materials systems are proven to possess improved thermoelectric performance, either by enhancing the power factor S (2) σ through quantum confinement, or decreasing thermal conductivity with numerous interfaces. The 2D tellurium, also called tellurene, is a newly discovered 2D material which showed great potential for thermoelectric applications. In this article, high-quality tellurene-like nanosheets are synthesized by the hydrothermal method and assembled into nanostructured bulk materials by low-temperature hot press, and their thermoelectric performance is investigated. Ultraviolet-ozone treatment is used to remove organic surface ligands. Doping is realized with surface doping with chalcogenidometalates. It is found that the Seebeck coefficient and the thermal conductivity of the nanosheet-assembled bulk samples increased by ≈20% and decreased by 43% compared to bulk tellurium, respectively. Meanwhile, the carrier mobility is approaching, yet still lower than bulk tellurium. Overall, the best bulk sample possesses a zT of 0.1 at room temperature which is comparable to bulk Te. By further improving the mobility, this solution processable material can provide useful thermoelectric performance for room-temperature applications.