Band Engineering of Dirac Materials for Device Applications

本研究提出了一种可扩展的方法，具有较低的复杂性，以调制二维（2D）狄拉克材料的能带结构，包括石墨烯，硅烯和过渡金属二硫属化物在电子和能源技术中的应用。将探索用金属纳米结构或聚合物分子对二维狄拉克材料进行图案化装饰，作为在保留其固有电学和光学性质的同时调谐二维狄拉克系统的选定区域中的能带隙的有效手段。将使用加拿大光源的X射线吸收和发射光谱对能带工程材料的详细电子结构进行表征，以揭示通过表面改性打开2D材料带隙的机制。这些能带工程2D狄拉克材料最终将用于生产高性能晶体管和太阳能电池器件。为了达到最佳的器件性能，将对器件操作参数（例如，晶体管器件的载流子迁移率和开/关比以及太阳能电池器件的能量转换效率）相对于表面覆盖率和装饰材料的类型进行定量分析。

This research proposes to develop a scalable method with less complexity to modulate the band structure of two dimensional (2D) Dirac materials including graphene, silicene, and transition metal dichalcogenides for applications in electronics and energy technologies. Patterned decoration of 2D Dirac materials with metallic nanostructures or polymer molecules will be explored as an effective mean to tune the energy band gap in selected areas of 2D Dirac systems while preserving their intrinsic electrical and optical properties. The characterization of detailed electronic structure for the band-engineered materials will be conducted using X-ray absorption and emission spectroscopy at the Canadian Light Source to shed light on the mechanism behind the opening of band gap in 2D materials by surface modification. These band-engineered 2D Dirac materials will ultimately be used to produce high performance transistor and solar cell devices. The quantitative analysis of the device operation parameters (for example, carrier mobility and on/off ration for transistor devices and energy conversion efficiency for solar cell devices) with respect to the surface coverage and type of decorating materials will be conducted in order to achieve the optimized device performance.