Strong Thermopower Enhancement and Tunable Power Factor via Semimetal to Semiconductor Transition in a Transition-Metal Dichalcogenide.
Electronic band engineering is a promising approach to enhance the thermopower of thermoelectric materials. In transition-metal dichalcogenides (TMDCs), this has so far only been achieved using their inherent semiconducting nature. Here, we report the thickness-modulated band engineering of nanosheets based on semimetallic platinum diselenide (PtSe2) resulting in a thermopower enhancement of more than 50 times than that of the bulk. We obtained this by introducing a semimetal to semiconductor (SMSC) transition resulting in the formation of a bandgap. This approach based on semimetallic TMDCs provides potential advantages such as a large variation of transport properties, a decrease of the ambipolar transport effect, and a high carrier density dependence of the transport properties. Our observations suggest that the SMSC transition in TMDCs is a promising and straightforward strategy for the development of two-dimensional nanostructured thermoelectric materials.
['Moon|Hongjae|H|', 'Bang|Joonho|J|', 'Hong|Seokkyoon|S|', 'Kim|Gwansik|G|', 'Roh|Jong Wook|JW|', 'Kim|Jeongmin|J|', 'Lee|Wooyoung|W|http://orcid.org/0000-0001-8406-4324']
thermopower semimetal to semiconductor transition transition-metal dichalcogenides electronic band engineering platinum diselenide