CuPc/MoS_(2)范德瓦耳斯异质结荧光特性  

Photoluminescence properties of CuPc/MoS_(2) van der Waals heterostructure

作　　者：孔宇晗 王蓉 徐明生 Kong Yu-Han;Wang Rong;Xu Ming-Sheng(State Key Laboratory of Silicon Materials,School of Micro-Nano Electronics,Department of Polymer Science and Engineering,Zhejiang University,Hangzhou 310027,China;Hangzhou Global Scientific and Technological Innovation Center,Zhejiang University,Hangzhou 311215,China)

机构地区：[1]浙江大学,高分子科学与工程学系,微纳电子学院,硅材料国家重点实验室,杭州310027 [2]浙江大学杭州国际科创中心,杭州311215

出　　处：《物理学报》2022年第12期475-480,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62090030,62090031,51872257,51672244);浙江省自然科学基金(批准号:LZ20F040001)资助的课题。

摘　　要：在众多二维材料中,过渡金属硫族化合物由于其具有独特的光电特性深受广大研究者喜爱.近年来,由二维过渡金属硫族化合物材料与有机半导体结合构建的范德瓦耳斯异质结受到极大的关注.这种异质结可以利用两者的优势对光电特性等性能进行调控,为许多基础物理和功能器件的构建提供了研究思路.本文构建了酞菁铜/二硫化钼(CuPc/MoS_(2))范德瓦耳斯异质结,并对其荧光特性进行了表征和分析.与单层MoS_(2)相比较发现,引入有机半导体CuPc后,异质结当中发生了明显的荧光淬灭现象.通过荧光分析,该现象可以用引入CuPc后异质结中负三激子与中性激子之比增加来解释.此外,通过第一性原理计算分析发现,引入CuPc会在MoS_(2)的禁带中引入中间带隙态,使得CuPc与MoS_(2)之间产生非辐射复合,这同样会导致荧光淬灭的发生.CuPc/MoS_(2)异质结的荧光淬灭现象可以为同类型范德瓦耳斯异质结的光电特性调控研究提供参考和思路.Among two-dimensional(2D)materials,transition metal chalcogenides(TMDs)have attracted much attention due to their unique photoelectric properties.On the other hand,organic molecules have the characteristics of flexibility,wide source,easy fabrication and low cost.The van der Waals heterostructure constructed by the combination of 2D TMDs and organic semiconductors has attracted enormous attention in recent years.When organic semiconductors combine with TMDs to form van der Waals heterostructure,the hybridization of organic molecules could improve the photoelectric properties and other properties by taking the advantages of these two materials,Therefore,the combination of organic semiconductor molecules and TMDs can provide a research platform for designing many basic physics and functional devices and interesting optoelectronic applications.In this work,CuPc/MoS_(2) van der Waals heterostructure is built,and its photoluminescence(PL)properties are investigated.It is observed that after introducing CuPc,a significant PL quenching phenomenon occurs in the heterostructure compared with the single layer MoS_(2) and pure CuPc only.After fitting the PL of CuPc/MoS_(2) heterostructure system and monolayer MoS_(2) only,the ratio of trion to neutral exciton is clearly increased in the heterostructure.Furthermore,it is found that two mid-gap states D1and D2 related to the CuPc are introduced into the band gap of MoS_(2) by first principle calculation.Through the charge density analysis,we find that the D1 state originates from the sp2 bonding state of the C-C bond while the D2 state comes from the anti-bonding state of the N-Cu bond.Meanwhile,the valence band maximum(VBM)and conduction band minimum(CBM)of CuPc/MoS_(2) heterostructure are derived from the bonding and anti-bonding states of MoS_(2),respectively.The charge transfer occurs between the mid-gap states of CuPc and MoS_(2).However,owing to different positions of charge density distribution of CBM,D2,D1 and VBM,the charge pathway is dominated by non-radiation recom

关 键 词：MoS_(2) CUPC 范德瓦耳斯异质结 光致发光 

分 类 号：O469[理学—凝聚态物理]