基于密度泛函理论下O和Na掺杂单层h-BN的电子结构和光学性质的分析  

Analysis of electronic structures and optical properties of O andNa doped monolayer h-BN based on density functional theory

作　　者：周国建 彭章娥 刘琳 罗剑平 ZHOU Guo-Jian;PENG Zhang-E;LIU Lin;LUO Jian-Ping(School of Urban Construction and Safety Engineering,Shanghai Institute of Technology,Shanghai 201418,China)

机构地区：[1]上海应用技术大学城市建设与安全工程学院,上海201418

出　　处：《原子与分子物理学报》2024年第6期6-12,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金重点项目(12032016)。

摘　　要：基于密度泛函理论的第一性原理方法研究了O、Na单掺杂及O和Na共掺杂单层h-BN的形成能、电子结构和光学性质.结果表明:单掺杂体系中,O掺杂N位置、Na掺杂B位置时,掺杂形成能最低;共掺杂体系中,O和Na邻位掺杂,掺杂形成能最低.与单层h-BN相比,引入杂质原子后的体系禁带宽度均减小,其中O掺杂为n型掺杂,Na掺杂为p型掺杂,而O和Na共掺h-BN体系为直接带隙材料,有利于提高载流子的迁移率.在光学性质方面,Na掺杂h-BN体系与O和Na共掺h-BN的静介电常数均增大,在低能区介电虚部和光吸收峰均发生红移,其中Na掺杂体系红移最为显著,极化能力最强.因此Na单掺和O和Na共掺有望增强单层h-BN的光催化能力,可扩展其在催化材料、光电器件等领域的应用.The formation energies, electronic structures and optical properties of O and Na single doped and O-Na co-doped monolayer h-BN are studied by using the first-principles method based on density functional theory.The results show that the doping formation energy is the lowest when O is doped at N position and Na is doped at B position;In the co-doped system, O and Na are ortho-doped, and the doping formation energy is the lowest. Compared with monolayer h-BN, the band gap width of the system is reduced after introducing impurity atoms, in which O doping is n-type doping, Na doping is p-type doping, and O-Na co-doped h-BN system is a direct band gap material, which is beneficial to improve carrier mobility. In terms of optical properties, the static dielectric constants of Na doped h-BN system and O and Na co-doped h-BN increase, and the imaginary parts of dielectric constants and optical absorption peaks in the low energy region are red-shifted. Among them, the Na doped system has the most significant redshift and the strongest polarization ability. Therefore, Na monodoping and O and Na co-doping are expected to enhance the photocatalytic ability of monolayer h-BN and hence expand its application in photocatalysis materials, optoelectronic devices and other fields.

关 键 词：单层h-BN 第一性原理 掺杂 电子结构 光学性质 

分 类 号：O649.1[理学—物理化学]