Strain Engineering in 2D Material‐Based Flexible Optoelectronics

Abstract

Flexible optoelectronics, as promising components hold shape‐adaptive features and dynamic strain response under strain engineering for various intelligent applications. 2D materials with atomically thin layers are ideal for flexible optoelectronics because of their high flexibility and strain sensitivity. However, how the strain affects the performance of 2D materials‐based flexible optoelectronics is confused due to their hypersensitive features to external strain changes. It is necessary to establish an evaluation system to comprehend the influence of the external strain on the intrinsic properties of 2D materials and the photoresponse performance of their flexible optoelectronics. Here, a focused review of strain engineering in 2D materials‐based flexible optoelectronics is provided. The first attention is on the mechanical properties and the strain‐engineered electronic properties of 2D semiconductors. An evaluation system with relatively comprehensive parameters in functionality and service capability is summarized to develop 2D materials‐based flexible optoelectronics in practical application. Based on the parameters, some strategies to improve the functionality and service capability are proposed. Finally, combining with strain engineering in future intelligence devices, the challenges and future perspective developing 2D materials‐based flexible optoelectronics are expounded.

In Situ Measurements of Strain Evolution in Graphene/Boron Nitride Heterostructures Using a Non-Destructive Raman Spectroscopy Approach

“…A custom-built mechanical device, the so-called ‘jig’, was designed for this study to be mounted directly onto the 3D-piezoelectric stage of a Raman spectroscopy system. This mechanical ‘jig’ is capable of applying a micron resolution displacement/bending, which is more precise compared with other reported studies [ 12 , 34 , 43 ]. This, in turn, allowed for a steady and accurate application of strain during the spectral measurements on the loaded thin films within the in situ Raman system.…”

Steering on Degrees of Freedom of 2D Van der Waals Heterostructures

“…Indeed, it is also of potential applications to make use of the strain caused by the fabrication process of 2D materials and/or 2D heterostructures, such as wrinkles, bubbles, and so on. [ 61,138,139 ] Under external strain, electronic band structure of materials, including the magnitude and type of bandgaps, would be changed by the stretched or compressed lattice structure of 2D materials, leading to modulate the electrical and optical properties. [ 139 ] Especially for 2D materials with strain sensitivity, such as MoS 2 , it is ideal to achieve modulations of photoelectric performance by strain engineering.…”

Strain-Enhanced Thermoelectric Performance in GeS2 Monolayer

“…Therefore, it is of great significance to improve its thermoelectric performance by adjusting the thermal transport properties of GeS 2 monolayers. It is worth mentioning that the electronic structures of 2D materials are easily affected by applied strains [ 26 , 27 , 28 ]. Strain engineering has been theoretically and experimentally proposed as a valid way to enhance the thermoelectric properties of 2D thermoelectric materials [ 29 , 30 ].…”