Strain Releasing of Flexible 2D Electronics through van der Waals Sliding Contact

Abstract

Two-dimensional (2D) materials have demonstrated promising potential for flexible electronics, owning to their atomic thin body thickness and dangling-bond-free surface. Here, we report a sliding contact device structure for efficient strain releasing. By fabricating a weakly coupled metal–2D junction with a van der Waals (vdW) gap in between, the applied strain could be effectively released through their interface sliding; hence minimized strain is transferred to the 2D lattice. Therefore, we observed stable device behavior with electrodes stretching over 110%, much higher than 2D devices using evaporated metal contacts. Furthermore, through multicycle straining–releasing measurements, we found the electrodes still form intimate contact with nearly constant contact resistance during sliding, confirming the optimization of device flexibility and electrical properties at the same time. Finally, we demonstrate this vdW sliding contact is a general device geometry and could be well-extended to various 2D or 3D bulk materials, leading to devices with much higher strain tolerance.

Dual Strategies of Metal Preintercalation and In Situ Electrochemical Oxidization Operating on MXene for Enhancement of Ion/Electron Transfer and Zinc‐Ion Storage Capacity in Aqueous Zinc‐Ion Batteries

“…During the charging and discharging processes, the calculated diffusion coefficient ( D ) values of VO x /Mn–V 2 C are 9.98 × 10 −8 –1.02 × 10 −9 cm 2 s −1 , which is obviously greater than those of VO x /V 2 CT x (8.16 × 10 −9 –1.48 × 10 −10 cm 2 s −1 ). The D values of VO x /Mn–V 2 C are comparable to those of other reported materials used in aqueous ZIBs (Figure 4e and Table S2 (Supporting Information)), [ 11,15,25,42,44,61,68–70 ] which indicates that VO x /Mn–V 2 C possesses the rapid diffusion of zinc ions. The higher D values can be attributed to preintercalated Mn 2+ extending the interlayer spacing of the prepared Mn–V 2 C, which provide ordered channels for the rapid diffusion of Zn 2+ .…”

Emerging Trends in 2D Flexible Electronics

“…This is a significant increase over the evaporated‐contact device used as the control and the earlier results. [ 153 ] The geometry of the metal‐semiconductor sliding contact may also serve as motivation for the study of fundamental physics, such as piezo‐electronics, carrier transport, spin injection or exciton relaxation. Only simple circuits using no more than three discrete MoS 2 transistors have been built so far on flexible substrates due to material and fabrication process limitations.…”

Van Der Waals Metal Contacts for Electronic and Optoelectronic Devices

“…Li et al reported a strain-releasing vdW sliding metal contact for flexible electronics, as shown in Figure a. With evaporated Au in contact with the graphene layer on a polyimide (PI) substrate, a strong interaction between the evaporated metal and 2D graphene can induce cracks in the graphene by applying strain.…”

“…(a) Schematic of stretchable electronics integrated with the vdW metal contact. Reproduced from ref . Copyright 2022 American Chemical Society.…”

“…Such vdW metal integrated memristors show significant improvements in both memristive performance and operation stability because of damage-free intact junctions and retarded chemical reactions between the contact and active layer. 25,91,92 Li et al 93 reported a strain-releasing vdW sliding metal contact for flexible electronics, as shown in Figure 23a. With evaporated Au in contact with the graphene layer on a polyimide (PI) substrate, a strong interaction between the evaporated metal and 2D graphene can induce cracks in the graphene by applying strain.…”