摘要
钛酸铅(PTO)因具有优异的铁电、压电特性及光学性质而备受关注.但B、N掺杂对顺电相PTO电子结构和光学性质的影响还不明确,因此,利用第一性原理对立方PTO开展准确的性质预测尤为必要.本文采用广义梯度近似的PBE泛函(GGA-PBE)和杂化泛函(HSE06)研究了B、N替位掺杂(B_(O)、N_(O))和O空位(V O)对PTO的基态性质、电子结构和光学性质的影响.研究表明:贫氧态的PTO比富氧态更容易形成杂质缺陷,且N_(O)缺陷最难形成.当B_(O)、N_(O)缺陷存在时,PTO的价带顶和导带底向低能量方向移动,在两者之间出现杂质能级,使其导电性能提高且含B_(O)的PTO为间接带隙半导体,而含N_(O)的PTO为直接带隙半导体.N_(O)体系在波长大约为230 nm处有最大吸收峰,该峰主要源于O 2p和Ti 3d之间的电子跃迁,且N_(O)体系对可见光的吸收能力最强,有望提高PTO的光催化能力.
Lead titanate(PTO)has attracted much attention due to its excellent ferroelectric,piezoelectric and optical properties.However,the effect of B or N doping on electronic structure and optical properties of PTO is still unclear.Herein,it is particularly necessary to accurately predict the properties of PTO via first-principles.The influences of B,N doping(B_(O),N_(O))and O vacancy(V O)on ground state,electronic structure and optical properties of PTO are studied by using generalized gradient approximation by Perdew,Burke,and Ernzerhof(GGA-PBE)and hybrid functional(HSE06).The results show that PTO in the oxygen-poor is easier to form impurity defects than in the oxygen-rich,and N_(O)defects are the most difficult to form.The valence band maximum and conduction band minimum move to low energy when B_(O)and N_(O)defects exist,and the impurity level appears between them,which improves the conductivity of PTO.B_(O)-doped PTO is an indirect band gap semiconductor,while N_(O)-doped PTO is a direct band gap semiconductor.N_(O)systems have a maximum absorption peak at a wavelength of about 230 nm,which is mainly due to the electronic transition between O 2p and Ti 3d.Moreover,N_(O)systems have the strongest absorption ability for visible light,which is expected to improve the photocatalytic ability of PTO.
作者
黄彬荣
文志勤
卢涛仪
邹正光
赵宇宏
HUANG Bin-Rong;WEN Zhi-Qin;LU Tao-Yi;ZOU Zheng-Guang;ZHAO Yu-Hong(School of Materials Science and Engineering,Guilin University of Technology,Guilin 541004,China;School of Materials Science and Engineering,North University of China,Taiyuan 030051,China)
出处
《原子与分子物理学报》
CAS
北大核心
2023年第4期159-165,共7页
Journal of Atomic and Molecular Physics
基金
广西自然科学基金(2019GXNSFBA245092)
桂林理工大学科研启动金(GUTQDJJ2019116)。
关键词
钛酸铅
第一性原理
电子结构
光学性质
PbTiO_(3)
First-principles
Electronic structure
Optical properties
