摘要
单层CuSe属于体相为非层状的二维材料,本质上具有金属性质,因此不适合在电子器件中应用.本文通过外部原子修饰的方法实现CuSe电子结构的改变,采用密度泛函理论的第一性原理研究了单层CuSe在顶位、中心和桥位添加第二周期原子后的能带结构,重点分析了单层CuSe添加Li和B原子的电子结构,包括能带结构、态密度、差分电荷密度和晶体轨道哈密顿布居分析.添加Li原子后,从能带结构的结果来看,三个位置都能实现CuSe由金属性转为半导体性,且Li原子更倾向修饰在CuSe的六角形中心,带隙约为1.77 eV;在Cu原子的顶部位置添加B原子也可以实现CuSe具有半导体性,带隙约为1.2 eV.通过差分电荷密度和晶体轨道哈密顿布居的结果来看,B原子用B-Se极性共价键结合在单层CuSe的顶部.第一原理揭示了从单层CuSe到Cu XSe(X=Li,B)的金属到半导体转变的实现,计算结果使CuSe在未来的电子设备中使用成为可能.
Original bulk phases of two-dimensional atomic crystal materials are layered.However,a few relevant researches show that some of two-dimensional material crystals have non-layered bulk phases.In this work we investigate monolayer CuSe which is non-layered,belonging in a new kind of honeycomb graphene analogue.Monolayer CuSe is not suitable for application in electronic devices because of its metallic nature.In order to find new two-dimensional atomic crystal materials with excellent performance suitable for application in electronic devices,we change CuSe from metal to semiconductor through external atom modification.The first principles study of density functional theory is conducted to ascertain the energy band structure of monolayer CuSe after second periodic atoms have been added to the top,center and bridge sites.The characteristics of monolayer CuSe with addition of Li or B atoms are studied,including energy band structure,the density of states,differential charge density,and crystal orbital Hamiltonian population.The results show that after adding Li atoms to CuSe,the CuSe transforms from metallic to semiconductive property at all three positions,and Li atom is more easily to be modified in the hexagonal center of CuSe,with band gap being about 1.77 eV,the Fermi level biased towards the top of the valence band.The CuSe with addition of Li atoms exhibits a p-type semiconductor property,so it is a direct bandgap semiconductor.Adding B atom to the top of Cu atom can also make CuSe semiconductive,with a band gap of about 1.2 eV,the conduction band minimum at the K point,and the valence band maximum at the G point.The CuSe with addition of B atoms belongs in an indirect band gap semiconductor,and the Fermi energy level is biased towards the conduction band minimum,exhibiting the characteristics of an n-type semiconductor.According to the results of differential charge density and crystal orbital Hamiltonian population,the B atom is bound to the top of the monolayer CuSe with the B-Se polar covalent bond.The fir
作者
莫秋燕
张颂
荆涛
张泓筠
李先绪
吴家隐
Mo Qiu-Yan;Zhang Song;Jing Tao;Zhang Hong-Yun;Li Xian-Xu;Wu Jia-Yin(Big Data Engineering College,Kaili University,Kaili 556011,China;School of Science,Kaili University,Kaili 556011,China;Test Center,Research Institute of China Telecom Corporation,Guangzhou 510630,China;School of Computer,Guangdong Vocational College of Post and Telecom,Guangzhou 510630,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第12期258-266,共9页
Acta Physica Sinica
基金
凯里学院校级规划课题(批准号:2022ZD05)
黔东南州科技计划(批准号:[2022]08)资助的课题。
关键词
单层CuSe
第一性原理
电子结构
monolayer CuSe
first-principles calculations
electronic structure
