Based on the first principles of density functional theory,in this paper,we calculate the differential charge densities,energy band structures,partial state densities and dielectric functions of Rb,O and H adsorbed graphene nanoscales,modulate the electronic and optical properties of graphene nanostrips,and study 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 ad-sorbed on graphene nanostrip,it becomes an n-type degenerate direct bandgap semiconductor with a bandgap value of 0.494 eV;Rb and O adsorbed graphene nanostrips become the p-type degenerate direct bandgap semi-conductors,and the bandgap value increases to 0.996 eV;after increasing the H adsorption on graphene nanos-trip,its semiconductor type becomes n-type direct bandgap semiconductor with the smaller bandgap of 0.299 eV,which is more conducive to the preparation of semiconductor luminescent devices.After adsorptions 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 in-creasing the adsorption of O atoms,O-2p contributes very actively near the Fermi energy level,and the hybrid-ization of C-2p,Rb-5s and O-2p electronic states promotes the impurity levels near the Fermi level to split into energy bands.After adding H atom adsorption,the Rb-4p contribution is blue-shifted,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 are clearly modulated.
关键词
石墨烯纳米带/能带结构/光学性质/分波态密度/第一性原理
Key words
Graphene nanoribbon/Energy band structures/Optical properties/Project density of states/First principle calculations
维普
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