Wang, Ying-YuYing-YuWangChen, Ding-RuiDing-RuiChenWu, Jen-KaiJen-KaiWuWang, Tian-HsinTian-HsinWangChuang, ChiashainChiashainChuangSSU-YEN HUANGHsieh, Wen-PinWen-PinHsiehMario HofmannYUAN-HUEI CHANGHsieh, Ya-PingYa-PingHsieh2023-07-182023-07-182021-08-2515306984https://scholars.lib.ntu.edu.tw/handle/123456789/633924We 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.enmultifunctional materials; strain sensors; structural health monitoring; thermoelectrics; tin diselenidejournal article10.1021/acs.nanolett.1c02331343875052-s2.0-85113926232https://api.elsevier.com/content/abstract/scopus_id/85113926232