Chang Shunyu, Yan Yongda, Geng Yanquan
The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang 150080, P. R. China.
Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, P. R. China.
Nano Lett. 2023 Oct 25;23(20):9219-9226. doi: 10.1021/acs.nanolett.3c01809. Epub 2023 Oct 12.
Strain engineering in two-dimensional materials (2DMs) has important application potential for electronic and optoelectronic devices. However, achieving precise spatial control, adjustable sizing, and permanent strain with nanoscale resolution remains challenging. Herein, a thermomechanical nanoindentation method is introduced, inspired by skin edema caused by mosquito bites, which can induce localized nanostrain and bandgap modulation in monolayer molybdenum disulfide (MoS) transferred onto a poly(methyl methacrylate) film utilizing a heated atomic force microscopy nanotip. Via adjustment of the machining parameters, the strains of MoS are manipulated, achieving an average strain of ≤2.6% on the ring-shaped expansion structure. The local bandgap of MoS is spatially modulated using three types of nanostructures. Among them, the nanopit has the largest range of bandgap regulation, with a substantial change of 56 meV. These findings demonstrate the capability of the proposed method to create controllable and reproducible nanostrains in 2DMs.
二维材料（2DMs）中的应变工程在电子和光电器件方面具有重要的应用潜力。然而，实现具有纳米级分辨率的精确空间控制、可调节尺寸和永久应变仍然具有挑战性。在此，受蚊虫叮咬引起的皮肤水肿启发，引入了一种热机械纳米压痕方法，该方法可利用加热的原子力显微镜纳米尖端在转移到聚甲基丙烯酸甲酯薄膜上的单层二硫化钼（MoS）中诱导局部纳米应变和带隙调制。通过调整加工参数，对MoS的应变进行调控，在环形扩展结构上实现了≤2.6%的平均应变。利用三种类型的纳米结构对MoS的局部带隙进行空间调制。其中，纳米坑的带隙调节范围最大，有56 meV的显著变化。这些发现证明了所提出的方法在二维材料中产生可控且可重复的纳米应变的能力。
