Shanghai Microsystem prepared graphene single crystal made a breakthrough in the study

Graphene research at Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences has again achieved major breakthroughs. Tang Shijie, State Key Laboratory of Information Functional Materials, and Graphene Superconductivity Laboratory, successfully achieved the high orientation growth of graphene single crystal on the surface of hexagonal boron nitride for the first time through the introduction of gaseous catalysts. The Shanghai Institute of Microsystem graphene team has carried out the epitaxial growth of graphene single crystal on the hexagonal boron nitride substrate and its performance characterization since 2011, and achieved a series of achievements. Based on the control of graphene nucleation in the early stage and the orientation relationship between single crystal and substrate, based on the introduction of acetylene as a carbon source and the introduction of silane as a catalyst, they were prepared by chemical vapor deposition Graphene single crystal, the growth rate than the previous literature reported two orders of magnitude increased, more than 90% of the graphene single crystal and boron nitride substrate strict orientation, presented by the Murray fringes caused by ~ 14nm two-dimensional super-crystal The lattice structure, the prepared graphene has a typical room temperature Hall mobility of more than 20,000 cm2 / V · s. Graphene is generally considered to be the most competitive electronic material for the continuation of Moore's Law in the post-silicon CMOS era due to its excellent electrical properties, superior thermal conductivity, and excellent mechanical properties. However, the electrical properties of graphene are greatly affected by the substrate. The charge impurities and phonon scattering will greatly reduce the electrical properties of graphene. The research shows that hexagonal boron nitride is an excellent substrate for graphene electronic devices because of its atom-level surface roughness, dangling bonds and excellent insulating properties. Direct growth of graphene single crystals on the surface of hexagonal boron nitride by chemical vapor deposition can avoid interface contamination and damage defects caused by physical transfer and provide material basis for its further application in the field of integrated circuits . However, the direct growth of graphene single crystals on such dielectric surfaces as hexagonal boron nitride has been a huge challenge in the field of graphene research due to the lack of catalytic capability of the substrate. The gas-catalyzed catalytic method proposed in this study has been patented and can provide new ideas and technical solutions for the preparation of high quality graphene single crystal thin films on dielectric substrates. This work has been funded by the Ministry of Science and Technology major projects, Chinese Academy of Sciences and Shanghai Municipal Science and Technology Commission related research projects. Schematic diagram of growth of graphene single crystals by gas phase catalysis (left) and comparison of single crystal size and growth rate with previous reported data (right)

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