Scientific observation, 20 18,13 (6): 40-41doi:10.15978/j.cnki.1673-.

Analysis of Hot Papers in China

Research status and prospect of two-dimensional materials

Xu ...

State Key Laboratory of Silicon Materials, School of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 3 10027.

Online: 2018-12-15

About the author

Postdoctoral fellow of Zhejiang University, assistant researcher, engaged in two-dimensional material preparation and device research, professor of School of Information and Electronic Engineering of Zhejiang University, mainly engaged in two-dimensional material and device research.

Two-dimensional materials are a general term for a large class of materials, which refers to the atomic layer thickness in which the material size is reduced to the limit in one dimension, while the material size is relatively large in the other two dimensions. The most typical and earliest two-dimensional material proved by experiments is graphene. In 2004, K. S. Novoselov and others published an article in Science, which reported that graphene was obtained by mechanically stripping highly oriented pyrolytic graphite, and proved its unique and excellent electrical properties. Since then, two-dimensional materials represented by graphene have developed rapidly, and new two-dimensional materials have mushroomed. Thanks to the quantum confinement effect in the thickness direction of the atomic layer, these two-dimensional materials show completely different properties from their corresponding three-dimensional structures, so they have attracted extensive attention in science and industry.

In addition to graphene, other two-dimensional materials include: single-element silylene, germanium alkene, stannene, boron alkene and black phosphorus, transition metal chalcogenides such as MoS2, WSe2, ReS2, PtSe2 and NbSe2, main group metal chalcogenides such as GaS, InSe, SnS and SNS, and other two-dimensional materials such as h-BN, CrI3 and NiPS3. These two-dimensional materials have completely different energy band structures and electrical properties, covering materials from superconductors, metals, semi-metals, semiconductors to insulators. Meanwhile, they also have excellent optical, mechanical, thermal and magnetic properties. By stacking different kinds of two-dimensional materials, more functional material systems can be built. Therefore, these materials are expected to be used in high-performance electronic devices, optoelectronic devices, spintronics devices, energy conversion and storage.

At present, the research on two-dimensional materials mainly focuses on preparation, characterization, modification, theoretical calculation and application exploration, and has made great progress. For example, in preparation, mechanical stripping method is widely used to prepare two-dimensional material samples for laboratory physical properties research and device fabrication; Graphene with large area, high quality and controllable layers and some transition metal chalcogenides can be prepared by chemical vapor deposition, which lays the foundation for commercial application. For the characterization of two-dimensional materials, researchers have established a series of characterization methods such as complementary spectra and electron transport. Modification is also a very important aspect of the development of two-dimensional materials. By doping, chemical modification, electrostatic control, alloying and other means, the shortcomings of materials can be avoided to the maximum extent and their advantages can be brought into play. Theoretical calculation plays an important role in the development of two-dimensional materials. Through theoretical calculation, we can find more new two-dimensional materials, predict their properties, explain the observed phenomena and guide the experimental design. In application, the construction of high-frequency transistors based on graphene, short-channel field effect transistors and tunneling transistors based on MoS2, and the realization of other high-efficiency light-emitting and light-detecting devices all show great application potential of two-dimensional materials.