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Applications of new exfoliation technique in study of two-dimensional materials

2018; Science Press; Volume: 67; Issue: 21 Linguagem: Inglês

10.7498/aps.67.20181636

1000-3290

Xu Hong sup sup, Meng Lei sup sup, Li Yang sup sup, Yang Tian-Zhong, Lihong Bao, Liu Guo-Dong, Zichang Lin, Tiansheng Liu, Jie Xing, Gao Hong-Jun, Zhou Xingjiang, Huang Yuan,

MXene and MAX Phase Materials

Since the discovery of graphene, mechanical exfoliation technology has become one of the important methods of preparing high-quality two-dimensional (2D) materials. This technology shows some unique advantages in the study of the intrinsic properties of 2D materials. However, traditional mechanical exfoliation method also has some obvious deficiencies, such as low yield ratio and small size of the resulting single-or few-layer flakes, which hinders the research progress in the field of 2D materials. In recent years, we made a series of breakthroughs in mechanical exfoliation technology, and independently developed a new type of mechanical exfoliation method with universality. The core of this new method is to enhance the van der Waals interaction between the layered material and the substrate by changing multiple parameters in the exfoliation process, thereby increasing the yield ratio and area of the monolayer. Taking graphene for example, we can now increase the size of graphene from micron to millimeter, increase over 100000 times in area, and yield ratio more than 95%, in the meantime graphene still maintains very high quality. This new mechanical exfoliation method shows great universality, and high-quality monolayer flake with a size of millimeters or more has been obtained in dozens of layered material systems including MoS2, WSe2, MoTe2, and Bi2212. More importantly, some special structures can be fabricated by optimizing exfoliation parameters, such as bubble and wrinkle structures, which paves the way for the study of these special material systems. Many scientific problems are still worth exploring in the mechanical exfoliation technology, and the breakthrough of this technology will greatly promote the research progress in the field of 2D materials.