非简谐振动和吸附对金属基外延石墨烯吸附系统电导率的影响  

The Effect of Non-harmonic Vibration and Adsorption on the Conductivity of Metal-Based Epitaxial Graphene Adsorption System

作　　者：申凤娟 郑瑞伦 SHEN Feng-juan;ZHENG Rui-lun(College of Electronic and Electrial Engineering/Chongqing University of Arts and Sciences,Chongqing Engineering Research Center of New Energy Storage Devices and Applications,Yongchuan Chongqing 402160,China)

机构地区：[1]重庆文理学院电子电气工程学院/重庆市高校新型储能器件及应用工程研究中心

出　　处：《西南大学学报（自然科学版）》2019年第11期64-72,共9页Journal of Southwest University(Natural Science Edition)

基　　金：重庆市基础与前沿研究项目(cstc2015jcyjA40054);重庆市教委科学技术研究项目(KJQN201801311)

摘　　要：考虑到吸附原子与外延石墨烯原子的相互作用以及石墨烯原子的非简谐振动,研究了外延石墨烯吸附系统的电导率随温度变化的规律.以吸附在Cu和Ni基外延石墨烯上的W原子的系统为例,探讨了原子非简谐振动和吸附对电导率的影响.结果表明:①金属基外延石墨烯吸附系统的电导率随温度升高而减小,不考虑声子电子的相互作用和吸附时,系统的电导率随温度升高而增大,但变化极小;②声子电子相互作用引起的电导率改变量随温度升高而减小,几乎与温度成反比;③吸附引起的电导率改变量在温度不太高(低于600 K)时可以忽略,而温度较高时则随温度升高而迅速增大,温度达到1000 K时,吸附对电导率的影响可占总量的4.35%;④原子非简谐振动对系统的电导率有重要影响.简谐近似时,电导率几乎与温度成反比.考虑到原子非简谐振动后,电导率比简谐近似的值增大,温度愈高,非简谐效应愈明显.In this paper,the interaction between adsorption and epitaxial graphene atoms and the non-harmonic vibration of atoms in graphene are considered,and the variation of the conductivity with the temperature of the epitaxial graphene adsorption system is studied.Taking the W atom adsorption system of Cu-and Ni-based epitaxial graphene as an example,the effect of anharmonic vibration and adsorption on the electrical conductivity of the system is discussed.The results show that the conductivity of the metal-based epitaxial graphene adsorption system decreases with increasing temperature and that when the phonon-electron interaction and adsorption are not considered,the conductivity of the system increases with temperature,but the change is very small.The change of conductivity caused by phonon-electron interaction decreases with the increase of temperature,almost in inverse proportion to temperature.The change of the conductivity caused by adsorption is almost independent of temperature,and is very small when temperature is not high(T<600 K).However,this change rapidly increases with the increase of temperature when the temperature is high(T≥1000 K),and the effect of adsorption on conductivity can account for 4.35%of the total.Anharmonic vibration of atoms has an important influence on the conductivity.In the simple harmonic approximation,the conductivity is almost inversely proportional to temperature.Considering the atomic anharmonic vibrational terms,the conductivity is slightly larger than the harmonic approximation.With higher temperature,the non-harmonic effect is more obvious.

关 键 词：外延石墨烯 电导率 吸附 非简谐效应 

分 类 号：O482.4[理学—固体物理]