2D mechano-thermoelectric heterojunctions for self-powered strain sensors
Ying-Yu Wang, Ding-Rui Chen, Jen-Kai Wu, Tian-Hsin Wang, Chiashain Chuang, Ssu-Yen Huang, Wen-Pin Hsieh, Mario Hofmann, Yuan-Huei Chang, Ya-Ping Hsieh*
Nano Lett., https://doi.org/10.1021/acs.nanolett.1c02331 (2021).
We here demonstrate the multifunctional properties of atomically thin heterojunctions that are enabled by strong interfacial interactions and their integration into ultra-high performance, self-powered sensors. Epitaxial alignment between tin diselenide and graphene through direct growth produces thermoelectric and mechanoelectric properties beyond the ability of either component. An unprecedented ZT of 2.43 originated from the synergistic combination of graphene’s high carrier conductivity and SnSe2 mediated thermal conductivity lowering. Moreover, strong interaction at the SnSe2/graphene interface produces stress localization that results in a novel 2D-crack-assisted strain sensing mechanism whose sensitivity (GF=450) is superior to all other 2D materials. Finally, the graphene-assisted growth process, permits the formation of high-quality heterojunctions directly on polymeric substrates for flexible and transparent self-powered sensors that achieve fast and reliable strain sensing from a small temperature gradient. Our work enhances the fundamental understanding of multifunctionality at the atomic scale and provide a route towards structural health monitoring through ubiquitous and smart devices.
Institute of Atomic and Molecular Sciences Academia Sinica
