| 六方氮化硼单层中一种(CN)3VB缺陷的第一性原理计算 |
| |
| 引用本文： | 孙志海,黄强,张颖,黄鹏儒,植慧茵,邹勇进,徐芬,孙立贤.六方氮化硼单层中一种(CN)3VB缺陷的第一性原理计算[J].物理学报,2021(3):78-90. |
| |
| 作者姓名： | 孙志海 黄强 张颖 黄鹏儒 植慧茵 邹勇进 徐芬 孙立贤 |
| |
| 作者单位： | 桂林电子科技大学材料科学与工程学院;广西师范大学物理科学与技术学院 |
| |
| 基金项目： | 国家重点研发计划(批准号:2018YFB1502103,2018YFB1502105);国家自然科学基金(批准号:51801041,551671062,5187011196,51971068);广西自然科学基金(批准号:2017JJB150085);广西科技计划(批准号:2018AD19052,AA19182014,AD17195073,AA17202030-1)资助的课题。 |
| |
| 摘 要： | 二维六方氮化硼(hBN)的点缺陷最近被发现可以实现室温下的单光子发射,而成为近年的研究热点.尽管其具有重要的基础和应用研究意义,hBN中发光缺陷的原子结构起源仍然存在争议.本文采用基于密度泛函理论的第一性原理计算,研究hBN单层中一种B空位附近3个N原子被C替代的缺陷(CN)3VB.在hBN的B空位处,3个N原子各自带一个在平面内的悬挂键及相应的未配对电子,而通过C替换可以消除未配对的电子.系统研究了(CN)3VB缺陷的几何结构、电子结构以及光学性质,结果表明,缺陷可以由一个对称的亚稳态经过原子结构弛豫变成1个非对称的、3个C原子连在一起的基态结构.缺陷的形成在hBN中引入了一些由缺陷悬挂σ键及重构的π键贡献的局域缺陷态.这些缺陷态可以导致能量阈值在2.58 eV附近的可见光内部跃迁.本文的工作有助于进一步理解hBN中点缺陷的构成及光学性质,为实验上探讨发光点缺陷的原子结构起源及其性质提供理论依据.
|
| 关 键 词： | 六方氮化硼 碳掺杂 电子结构 单光子发射 |
First-principle calculation study of(C)V defect in hexagonal boron nitride monolayer |
| |
| Sun Zhi-Hai,Huang Qiang,Zhang Ying,Huang Peng-Ru,Zhi Hui-Yin,Zou Yong-Jin,Xu Fen,Sun Li-Xian.First-principle calculation study of(C)V defect in hexagonal boron nitride monolayer[J].Acta Physica Sinica,2021(3):78-90. |
| |
| Authors: | Sun Zhi-Hai Huang Qiang Zhang Ying Huang Peng-Ru Zhi Hui-Yin Zou Yong-Jin Xu Fen Sun Li-Xian |
| |
| Affiliation: | (Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials,Guangxi Key Laboratory of Information Materials,School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China;School of Physics and Technology,Guangxi Normal University,Guilin 541004,China) |
| |
| Abstract: | The point defect of two-dimensional hexagonal boron nitride(hBN) has recently been discovered to achieve single photon emission at room temperature,and it has become a research hotspot.Despite its important fundamental and applied research significance,the origin of the atomic structure of luminescence defects in hBN is still controversial.In this paper,first-principle calculations based on density functional theory are used to study a defect(CN)3VB in the hexagonal boron nitride monolayer(hBN) where three N atoms near the B vacancy are replaced by C atoms.At the B vacancy of hBN,the three N atoms each carry an in-plane dangling bond and the corresponding unpaired electron,and the unpaired electron can be eliminated by C substitution.We systematically study the geometric structure,electronic structure and optical properties of(CN)3VB defects,analyze the thermodynamic stability of defects through the calculation of the atomic structure,formation energy,and charge state of the defect,and analyze the position in the band gap and its atomic orbital contribution of defect state through energy band structure and wave function.We also analyze its optical properties through dielectric function and absorption coefficient,and predict its luminous photon energy.The results show that the defect can change from a symmetric metastable state to an asymmetric ground state structure with three C atoms connected together through atomic structure relaxation.The formation energy of asymmetric(CN)3VB is 7.94 eV,which is 3.72 eV lower than that of symmetric one.The formation of defects introduces some local defect states contributed by defect dangling σ bonds and reconstructed 7 t bonds in hBN.The defects have valence states between-2 and +2,and the thermodynamic transition energy level of asymmetric(CN)3VB is higher than that of symmetric(CN)3VB.In the transition from the metastable state to the ground state,these defect states can redshift the light absorption boundary of hBN,enhance the absorption intensity of visible light by hBN,and cause internal optical transitions.Among them,there is a visible light transition with an energy threshold around 2.58 eV in the asymmetry(CN)3VB defect.Single boron atom vacancy defect and(CN)3VB have optical transitions near infrared and ultraviolet energy,respectively.The present work will help to further understand the composition and optical properties of point defects in hBN,and provide a theoretical basis for experimentally exploring the origin and properties of the atomic structure of light-emitting point defects. |
| |
| Keywords: | hexagonal boron nitride carbon doping electronic structure single photon emission |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《物理学报》浏览原始摘要信息 |
|
点击此处可从《物理学报》下载免费的PDF全文 |
|
