石墨烯纳米片电子结构和量子输运特性第一原理研究  

First-principles study on electronic structure and quantum transport property of graphene nanoplatelets

作　　者：赵磊 孙伟峰[1] 杨佳明[1] ZHAO Lei;SUN Wei-Feng;YANG Jia-Ming(Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China)

机构地区：[1]哈尔滨理工大学电气与电子工程学院工程电介质及其应用教育部重点实验室黑龙江省电介质工程重点实验室,哈尔滨150080

出　　处：《原子与分子物理学报》2018年第6期963-969,共7页Journal of Atomic and Molecular Physics

基　　金：中国博士后科学基金(2013M531058);黑龙江省普通本科高等学校青年创新人才培养计划(UNPYSCT-2016162)

摘　　要：用基于密度泛函理论的原子紧束缚方法计算研究单层石墨烯纳米圆片和纳米带的电子结构,并结合第一原理和非平衡函数法计算量子输运特性.通过电子能态和轨道密度分布研究纳米碳原子层的电子成键状态,结合电子透射谱、电导和电子势分布分析电子散射与输运机制.石墨烯纳米带和纳米圆片分别呈现金属和半导体的能带特征,片层边缘上电极化分别沿垂直和切向方向,电子电导出现较大的差异,来源于石墨烯纳米圆片边缘的突出碳原子环对电子的强散射.石墨烯纳米带的电子透射谱表现为近似台阶式变化并在费米能级处存在弹道电导峰,而石墨烯纳米圆片的电子能带和透射谱在费米能级处开口并且因量子限制作用呈现更加离散的多条高态密度窄能带和尖锐谱峰.The electronic structures and quantum transport properties of graphene circle nanoplatelet and nanoribbon are theoretically studied by density-functional-based tight binding method combined with non-equilibrium Green's function.The electron eigen energy and orbital spacial distribution are analyzed to investigate the electronic bonding states of carbon atomic layer,and the transmission spectrum and electrical conductivity are calculated to explore electron scattering and transport mechanism based on the electronic potential field.The graphene nanoribbon and circle nanoplatelet represent metallic and semiconductor characteristics of electron energy bands respectively with normal and tangential electric polarizations at carbon layer edge.Graphene circle nanoplatelet exhibits remarkably smaller electrical conductivity compared with graphene nanoribbon,due to the substantial electron scattering by unsaturated chemical bonds of carbon atoms at the edge of circle nanoplatelet.Graphene nanoribbon presents step like transmission spectrum and characteristic impact peak at Fermi level,while the electron energy states and transmission function of circle nanoplatelet are respectively discrete to higher density energy bands and sharper spectral peaks resulting from specific quantum confinement.

关 键 词：石墨烯纳米颗粒 电子能带 电子输运 第一原理计算 

分 类 号：TQ174[化学工程—陶瓷工业]