二维黑磷的光学性质

黑磷是继石墨烯、过渡金属硫族化合物(TMDCs)之后又一个备受关注的二维材料.黑磷从单层到块材都是直接带隙半导体,且带隙从单层的1.7 eV一直随着层数的增加而减小,到块材则变为0.3 eV,涵盖了可见光到中红外波段,恰好填补了石墨烯和过渡金属硫族化合物的带隙在该波段的空白.同时,黑磷还具有很高的载流子迁移率、良好的调控性、面内各向异性等优异特性,很快便引起了人们广泛的研究兴趣.本论文主要介绍了当前有关二维黑磷光学性质方面的研究进展,包括黑磷的本征光学性质,如带间跃迁吸收、激子、光致发光、光学性质的稳定性;外界微扰,如应变、电场等对黑磷光学性质的影响;最后做了总结与展望.希望本文对黑磷光学性质研究的综述,能够引起对黑磷研究的更广泛兴趣.

Optical properties of two-dimensional black phosphorus

Recently,black phosphorus(BP),an emerging layered two-dimensional(2D)material,has aroused much research interest.Distinguished from most of other 2D materials,BP is always a direct bandgap semiconductor regardless of the thickness,with the bandgap ranging from 0.3 eV(bulk)to 1.7 eV(monolayer),which is just fill the gap in the bandgap between graphene and transition metal dichalcogenides(TMDCs)in this frequency range.Besides,the BP exhibits many intriguing properties,such as high carrier mobility,highly tunable and anisotropic physical properties,which render the BP another star 2D material following graphene and TMDCs.In this review,we mainly focus on the advances in the optical properties of 2D BP,with the content covering the intrinsic optical properties and external perturbation effects on optical properties.Regarding the intrinsic optical properties,we introduce the anisotropic and layer-dependent optical absorption from interband transitions,the layer-dependent exciton binding energy and exciton absorption,visible-to-infrared photoluminescence,and stability of absorption and photoluminescence.As for external perturbation effects on optical properties,we introduce in-plane uniaxial and biaxial strain effects,gate-induced quantum confined Franz-Keldysh effect and Burstein-Moss effect.And finally we give a brief summary and outlook,pointing out some several interesting and important issues of BP,which need further studying urgently such as hyperbolic plasmons,intersubband transitions,optical properties in heterostructures and twist angle moirésuperlattice and so on.This review gives an overview of the optical properties of BP and is expected to arouse the interest in further studying the BP.