摘要
文章基于密度泛函理论,研究了本征及Nb,Fe单原子掺杂单层MoSe_(2)的电子结构及光学性质。计算发现,本征单层MoSe_(2)和Nb-MoSe_(2)为直接带隙半导体,Fe-MoSe_(2)为间接带隙结构;Fe-MoSe_(2)较本征单层MoSe_(2)导电性大大提高,实现了由半导体向半金属的过渡。由态密度分析得出了本征及Nb,Fe单原子掺杂单层MoSe_(2)能量状态主要由Mo 4d,Se 4p轨道电子所贡献的结论,并对各原子掺杂体系轨道电子的能量贡献和掺杂类型做了探讨。此外,还详细分析了费米能级附近的自旋态密度、杂质带、磁性之间的联系。光学性质方面,比较了本征单层MoSe_(2)与各掺杂体系的复介电常数和光吸收系数,在红外光区Fe-MoSe_(2)的吸收系数高于本征单层MoSe_(2)。本征单层MoSe_(2)的光吸收系数为9.69×10^(4)cm^(-1),是区域最大吸收峰。上述研究表明,通过对单层MoSe_(2)的Nb,Fe掺杂可使电子输运特性得到了增强,为高活性自旋电子和光电子器件设计和研究开辟了新的前景。
Based on density functional theory(DFT),CASTEP package is applied to study the electronic structure and optical properties of the single-layer MoSe_(2),Nb-MoSe_(2)and Fe-MoSe_(2).It is found through calculation that MoSe_(2)and Nb-MoSe_(2)are semiconductor materials with direct band gap,Fe-MoSe_(2)with indirect one.The conductivity of Fe-MoSe_(2)is much higher than that of MoSe_(2),and the transition from semiconductor to semi-metal is realized.A conclusion is reached through density of states that the energy state of intrinsic monolayer MoSe_(2)is mainly from Mo 4d and Se 4p orbital electrons.The orbital electronic energy contribution and hybridization type are also discussed.In addition,the relationship among the spin states density near the Fermi level,the impurity band and magnetism is analyzed in detail.As for the optical properties,dielectric constant and optical absorption coefficient of intrinsic monolayer MoSe_(2)and the dopant systems are compared.In the infrared region,the absorption coefficient of Fe-MoSe_(2)is higher than MoSe_(2),with the maximum absorption coefficient 9.69×10^(4)cm^(-1).The electron transport properties are enhanced by doping Nb,Fe with MoSe_(2),which opens up new prospect for the design and research of highly active spintronic and optoelectronic devices.
作者
周予宁
李明
ZHOU Yu-ning;LI Ming(School of Chemical Engineering,North China University of Science and Technology,Tangshan 063210,China)
出处
《唐山学院学报》
2023年第3期55-62,共8页
Journal of Tangshan University
