Two-Dimensional Mechano-thermoelectric Heterojunctions for Self-Powered Strain Sensors
Journal
Nano letters
Journal Volume
21
Journal Issue
16
Date Issued
2021-08-25
Author(s)
Wang, Ying-Yu
Chen, Ding-Rui
Wu, Jen-Kai
Wang, Tian-Hsin
Chuang, Chiashain
Hsieh, Wen-Pin
Hsieh, Ya-Ping
Abstract
We here demonstrate the multifunctional properties of atomically thin heterojunctions that are enabled by their strong interfacial interactions and their application toward self-powered sensors with unprecedented performance. Bonding between tin diselenide and graphene produces thermoelectric and mechanoelectric properties beyond the ability of either component. A record-breaking ZT of 2.43 originated from the synergistic combination of graphene's high carrier conductivity and SnSe2-mediated thermal conductivity lowering. Moreover, spatially varying 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, a graphene-assisted growth process permits the formation of high-quality heterojunctions directly on polymeric substrates for flexible and transparent sensors that achieve self-powered strain sensing from a small temperature gradient. Our work enhances the fundamental understanding of multifunctionality at the atomic scale and provides a route toward structural health monitoring through ubiquitous and smart devices.
Subjects
multifunctional materials; strain sensors; structural health monitoring; thermoelectrics; tin diselenide
Type
journal article