Won Kyuyeon, Lee Chanwoo, Jung Jaehyuck, Kwon Sanghyuk, Gebredingle Yisehak, Lim Jang Gyun, Kim Moon Ki, Jeong Mun Seok, Lee Changgu
School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
Adv Mater. 2022 Jul;34(30):e2200946. doi: 10.1002/adma.202200946. Epub 2022 Jun 16.
Graphene is known as a superstiff and extremely strong material. Hence, applying strains greater than 1% to graphene and simultaneously measuring changes in its physical properties has been challenging because of the limited methodologies for measuring both high strain and other physical properties. Here, Raman scattering measurement of suspended graphene under extremely high biaxial strain as large as 6.1% using an atomic force microscopy (AFM)-Raman spectroscopy measurement tool is reported. Nanoindentation is performed using AFM tips machined to have a flat top and a hole shape, resulting in a strained graphene area sufficiently large to enable the acquisition of a Raman signal. At the same time, the laser light is focused on the strained flat area of the graphene membrane. The Raman signals of the G and 2D bands of graphene are redshifted by 282 and 684 cm , respectively, which is unprecedented for graphene. This measurement technique provides an effective methodology to measure variations in the physical properties of atomically thin materials under superhigh strain.
石墨烯被认为是一种超硬且极其坚固的材料。因此，由于测量高应变和其他物理性质的方法有限，对石墨烯施加超过1%的应变并同时测量其物理性质的变化一直具有挑战性。在此，报道了使用原子力显微镜（AFM）-拉曼光谱测量工具对高达6.1%的极高双轴应变下的悬浮石墨烯进行拉曼散射测量。使用加工成具有平顶和孔形状的AFM尖端进行纳米压痕，从而产生足够大的应变石墨烯区域，以获取拉曼信号。同时，激光聚焦在石墨烯膜的应变平面区域上。石墨烯的G带和2D带的拉曼信号分别红移了282和684 cm，这对于石墨烯来说是前所未有的。这种测量技术提供了一种有效的方法来测量超高应变下原子级薄材料物理性质的变化。
