On the morning of February 24, 2017, the 2016 Jiangsu Provincial Science and Technology Awards Conference was held in the Jiangsu Provincial Political Consultative Conference Hall. Li Qiang, Secretary of the Jiangsu Provincial Party Committee, and Shi Taifeng, Governor of Jiangsu Province, attended the conference and issued award certificates to the winning representatives. The meeting was chaired by Executive Vice Governor Huang Lixin. The project "Detection and regulation of optical properties of two-dimensional materials-precious metal composite system" jointly declared by our company and Southeast University won the third prize of Jiangsu Province Science and Technology Award in 2016. The company's project team attended the award conference.

Project Description：Two-dimensional nanomaterials such as graphene, disulfide/molybdenum selenide, etc. have attracted extensive attention at home and abroad due to their unique properties. Among them, graphene has become an outstanding representative due to its outstanding electrical, optical, thermal and mechanical properties, and its discoverer won the Nobel Prize in Physics in 2010. Based on the excellent electrical properties of graphene, it can replace silicon materials for the preparation of microelectronic devices such as transistors; based on its ultra-broadband optical response, it can be used to prepare full-band photodetectors (ultraviolet to far-infrared region), overcoming traditional The disadvantage of the small detection range of the device. Based on its high light transmittance, extremely high conductivity, and high mechanical strength, it can be used for the development of touch screens and other devices (currently, graphene-based mobile phones and display touch screens have been developed). Based on its saturable absorption performance, ultra-high frequency photoelectric modulation has been realized, which can greatly improve the ability of optical communication (network communication).
However, in the large-scale application and industrialization of two-dimensional materials such as graphene, the research and detection of their basic properties, especially optical and optoelectronic properties, are crucial. At the same time, how to combine graphene with other semiconductor or metal materials to exert the excellent electrical properties of graphene and make up for the weak optical absorption phenomenon caused by the defect of its zero band gap is also the focus of current scientific research. This project has been devoted to the study of optical properties of two-dimensional materials such as graphene since 2010, and combined them with metal nanostructures to improve the optical and optoelectronic properties of two-dimensional materials. The main research results obtained by the project include:
1. It is proposed to use optical contrast to accurately determine the number of layers of two-dimensional materials such as graphene, and to control the performance of two-dimensional materials by controlling the number of layers. Optical contrast method is currently the mainstream method for determining the number of layers of two-dimensional materials. The project team members, as the first drafters, have written the standard document of "Determination of the Number of Graphene Layers by Optical Method", which has been submitted to the National Standards Committee through the Nano Standardization Committee, and has been approved for project establishment. The applicant also proposed a method to precisely control (Layer by Layer) the number of molybdenum disulfide layers using plasma etching, and studied the changes of the material's optical properties such as fluorescence and Raman with the thickness of the material. This method does not introduce any defects in molybdenum sulfide, and can be operated in a wide range. It can be used to prepare two-dimensional materials of any structure and thickness with lithography and other methods. It is very meaningful for two-dimensional materials.
2. Combine graphene and metal nanoparticles to enhance graphene optical absorption by using metal surface plasmon effect. The project team used nanoimprint technology to successfully fabricate gold nano-half-shell arrays with orderly and controllable structure. Combining ordered arrays of metal nanoparticles with graphene, on the one hand, enhances the optical absorption of graphene, and on the other hand, graphene acts as an ultra-thin two-dimensional surface passivation layer, making the surface plasmon effect of metal nanostructures. It has been significantly improved, and important progress has been made in fluorescent biological detection and calibration.
3. Use Raman spectroscopy to study defects in graphene, and control the performance of graphene through defect engineering. Defects in 2D materials have important effects on their properties. The project team used Raman spectroscopy to detect trace defects in graphene, and found that defects are an important factor limiting the further improvement of electrical properties. At the same time, the project team is also committed to regulating the optical and optoelectronic properties of two-dimensional materials such as graphene through defect engineering.