Two-dimensional transition-metal dichalcogenide (2D TMD) layers are highly attractive for emerging stretchable and foldable electronics owing to their extremely small thickness coupled with extraordinary electrical and optical properties. Although intrinsically large strain limits are projected in them (i.e., several times greater than silicon), integrating 2D TMDs in their pristine forms does not realize superior mechanical tolerance greatly demanded in high-end stretchable and foldable devices of unconventional form factors. In this article, we report a versatile and rational strategy to convert 2D TMDs of limited mechanical tolerance to tailored 3D structures with extremely large mechanical stretchability accompanying well-preserved electrical integrity and modulated transport properties. We employed a concept of strain engineering inspired by an ancient paper-cutting art, known as kirigami patterning, and developed 2D TMD-based kirigami electrical conductors. Specifically, we directly integrated 2D platinum diselenide (2D PtSe2) layers of controlled carrier transport characteristics on mechanically flexible polyimide (PI) substrates by taking advantage of their low synthesis temperature. The metallic 2D PtSe2/PI kirigami patterns of optimized dimensions exhibit an extremely large stretchability of ∼2000% without compromising their intrinsic electrical conductance. They also present strain-tunable and reversible photoresponsiveness when interfaced with semiconducting carbon nanotubes (CNTs), benefiting from the formation of 2D PtSe2/CNT Schottky junctions. Moreover, kirigami field-effect transistors (FETs) employing semiconducting 2D PtSe2 layers exhibit tunable gate responses coupled with mechanical stretching upon electrolyte gating. The exclusive role of the kirigami pattern parameters in the resulting mechanoelectrical responses was also verified by a finite-element modeling (FEM) simulation. These multifunctional 2D materials in unconventional yet tailored 3D forms are believed to offer vast opportunities for emerging electronics and optoelectronics.
Bibliographical noteFunding Information:
Y.J. acknowledges financial support from the University of Central Florida (grant no. 20080742 and VPR AECR award). The work at the University of Central Florida was also supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (no. 20173010013340, Y.J. and S.S.H.). The research at Seoul National University was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (grant nos. 2018M3D1A1058794 and 2017R1A5A1014862; SRC program: vdWMRC center). Also, the work at Seoul National University was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (no. 20173010013340). K.H.O. was supported by the project titled "Development of cleanup technology for spilled oil and floating HNS using nanostructured structures", funded by the Korea Coast Guard of the Korean government.
Copyright © 2019 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering