石墨烯纳米带光电特性及其应力调控研究

石墨烯纳米带是继碳纳米管后备受关注的新型准一维量子线, 人们已采用掺杂、边缘原子修饰以及外场等方法调控其微结构、电学和光学性质, 本项目研究应力新方法调控中的一些基本物理问题．拟采用紧束缚近似配合基于密度泛函的第一性原理计算相互验证, 利用非平衡格林函数方法及半导体带间跃迁理论, 研究石墨烯纳米带在应力作用下的原子构型、能带结构、载流子输运性质以及光学性质相对于无应力情形的变化规律．从理想完整条带受均匀应力作用的简单情形出发, 逐步过渡到应力作用下边缘或内部吸附杂质原子、存在少数碳原子空位、计入电子-电子相互作用、自旋-轨道互作用以及外加电磁场辐照等复杂情形．探索石墨烯纳米带在应力作用下的晶格弹性形变、能带结构、量子输运性质和光学性质之间的定量关系, 相关研究可能展现纳米(光)电子学及电子力学的一些新量子现象和概念, 并可能从原理上设计一些功能可调的新型电子、光电子器件和应力传感器等。

Graphene nanoribbons are world-concerned new type of quasi-one-dimensional quantum wires after carbon nanotubes. The microstructures, electronic and optical properties of graphene nanoribbons have been manipulated in all kinds of methods, such as doping, edge atom modifications and external fields. This project investigates the fundamental physical problems of manipulations based on external strains. Combining with the tight-binding approximation and the first-principle calculations based on density-functional theory, and using the method of nonequilibrium Green's function and the intersubband transitional theory of semiconductors under the dipole transition approximation, we should investigate the atomic configurations, electronic structures, electron transport and optical properties of graphene nanoribbons under the external uniaxial strains. Starting from the simple case about the transport and optical properties of the uniaxial strained ideal graphene nanoribbons, we would focus our attention on the complex cases, such as graphene nanoribbons with impurities at the edges or inner, a minority of carbon vacance, electron-electron correlation, spin-orbit interaction and the external electromagnetic fields irradiation, and so on. The investigation about the quantitatively relations among the elastic deformation of lattice, electronic structure, electron transport and optical properties of graphene nanoribbons under the external strains, may shed some light on brand new quantum phenomenon and concepts of nano-optoelectronics and electromechanics, and will be useful in the design of new types of electronic and optoelectronic devices other than the strain sensors.