Rb吸附石墨烯纳米带电子性质和光学性质的研究

本文基于密度泛函理论的第一性原理方法了计算了Rb、O和H吸附石墨烯纳米带的差分电荷密度、能带结构、分波态密度和介电函数，调制了石墨烯纳米带的电子性质和光学性质，给出了不同杂质影响材料光学特性的规律.结果表明本征石墨烯纳米带为n型直接带隙半导体且带隙值为0.639 eV；Rb原子吸附石墨烯纳米带之后变为n型简并直接带隙半导体，带隙值为0.494eV；Rb和O吸附石墨烯纳米带变为p型简并直接带隙半导体，带隙值增加为0.996eV；增加H吸附石墨烯纳米带后，半导体类型变为n型直接带隙半导体，且带隙变为0.299eV，带隙值相对减小，更有利于半导体发光器件制备.吸附Rb、O和H原子后，石墨烯纳米带中电荷密度发生转移，导致C、Rb、O和H之间成键作用显著.吸附Rb之后，在费米能级附近由C-2p、Rb-5s贡献；增加O原子吸附之后，O-2p在费米能级附近贡献非常活跃，杂化效应使费米能级分裂出一条能带；再增加H原子吸附之后，Rb-4p贡献发生蓝移，O-2p在费米能级附近贡献非常强，费米能级分裂出两条能带.Rb、O和H的吸附后，明显调制了石墨烯纳米带的光学性质.

The electronic and optical properties of Rubidium adsorbed graphene nanoribbons

Based on the first principles of density functional theory, this paper calculates the differential charge density, energy band structure, wave-by-wave state density and dielectric function of Rb, O and H adsorbed graphene nanoscales, modulates the electronic and optical properties of graphene nanostrips, and gives the laws of different impurities affecting the optical properties of materials. The results show that the intrinsic graphene nanostrip is an n-type direct bandgap semiconductor with a bandgap value of 0.639 eV. After the Rb atom adsorbed the graphene nanostrip, it became an n-type Deliterate direct bandgap semiconductor with a bandgap value of 0.494eV; Rb and O adsorbed graphene nanostrips became p-type deliterate direct bandgap semiconductors, and the bandgap value increased to 0.996eV; after increasing the H adsorption graphene nanostrip, the semiconductor type became n-type direct bandgap semiconductors, and the bandgap became 0.299eV, and the bandgap value was relatively reduced, which was more conducive to the preparation of semiconductor luminescent devices. After adsorption of Rb, O and H atoms, the charge density in the graphene nanoribbon shifts, resulting in significant bonding between C, Rb, O and H. After adsorption of Rb, C-2p and Rb-5s contribute near the Fermi energy level; After increasing the adsorption of O atoms, O-2p contributes very actively near the Fermi energy level, and the hybridization effect splits the Fermi energy level into an energy band; After adding H atom adsorption, the Rb-4p contribution is blueshifted, and the O-2p contribution is very strong near the Fermi energy level, and the Fermi energy level splits into two energy bands. After the adsorption of Rb, O and H, the optical properties of graphene nanostrips were clearly modulated.