Professor Stephen J. Pennycook and Dr Haijun Wu from the National University of Singapore's (NUS) Department of Materials Science and Engineering collaborated with Professor Li-Dong Zhao from the School of Materials Science and Engineering in Beihang University, China, in a recent Science paper about high-performance low-cost thermoelectrics, selenium-doped tin sulphide (Se-SnS) crystals.
With more than 60 per cent of input energy being lost as waste heat, there is a compelling need for high performance thermoelectric materials that can directly and reversibly convert heat to electrical energy. Practical realisation of thermoelectric materials is severely restricted by the thermoelectric materials' disadvantages of high-cost, earth-scarcity, environmental-toxicity, etc, thus high-performance low-cost thermoelectrics are in high demand.
The researchers reported the high-performance SnS thermoelectric crystals combining the desirable features of low-cost, earth-abundant materials and environmental friendliness. For the first time, they discovered the interplay of triple electronic bands leading to the high performance of thermoelectric SnS crystals, which is promoted by Se alloying. Furthermore, Se alloying plays a second important role in lowering the thermal transport.
The NUS Engineering team proved the existence of Se substitutions in the SnS lattice by directly seeing, for the first time, the substitutional point defects through aberration-corrected scanning transmission electron microscopy (STEM).
The work on high thermoelectric performance on SnS crystals was published in Science online on 27 September 2019.
For more details about the research and the journal paper, please visit: https://science.sciencemag.org/content/365/6460/1418