Realization of Ultrahigh Strain Modulation in Two‐Dimensional β‐InSe Layers

Abstract

Abstract 2D materials are regarded as ideal candidates for fabricating flexible devices in electronics, due to their intrinsic clean surface and malleability. However, due to the weak interaction between 2D materials and the substrates underneath, bending or stretching will inevitably cause severe slippage, which degrades the device's performance or even leads to failure. The realization of no slippage between 2D materials and substrates under ultrahigh strain has become a key topic in the field of flexible electronics. Here, a strategy to overcome this limitation, by which strain can be effectively transferred to 2D materials is demonstrated. By applying this improved method to few‐layer β‐InSe, it is found that the loaded strain reaches as high as 7.2% without any slippage, along with an apparent redshift of ≈4.18 cm−1 in Raman scattering signals. The evolution trend of bandgap observed in the luminous properties of β‐InSe is consistent with the author's density functional theory (DFT) calculations. This convenient method can be intensively expanded to other van der Waals (vdW) layered materials and sheds light on flexible electronic applications.

Keywords

• density functional theory calculations
• indium selenide
• optical characterization
• strain engineering