摘要
贵金属和二维半导体构建的异质结为等离激元纳米结构产生的热载流子提供了独特的电荷传输路径,有望应用于各种等离激元和光电子器件.然而,传统异质结构的电荷转移速度和效率通常受限于有限的界面面积和不可避免的界面污染.本文中,具有原子级清洁和较大接触界面的新型Au@MoS_(2)核壳异质结构能够实现超快和高效的热电子转移.飞秒瞬态吸收光谱研究表明,Au@MoS_(2)中从金纳米颗粒到MoS_(2)的热电子注入时间常数小于244 fs,而机械转移方法制备的Au/MoS_(2)对照样品的热电子注入时间常数为493 fs,同时,电荷转移效率从Au/MoS_(2)的3.33%提升至Au@MoS_(2)的25.3%.开尔文探针力显微镜和离散偶极近似研究进一步证明了上述结果,明显改善的电荷转移归因于原子级清洁和完全封装的异质结界面.这项研究提供了贵金属-二维半导体异质结构内固有电荷转移的基本理解,从而展现了Au@MoS_(2)这一新型异质结结构在等离激元和光电子器件中的应用前景.
Heterostructures constructed by noble metals and two-dimensional(2D)semiconductors offer a unique charge transport path to collect hot carriers from plasmonic nanostructures and thus are promising for various plasmonic and optoelectronic devices.However,the desired charge transfer speed and efficiency of the conventional heterostructures are usually restricted by the limited interface area and inevitable interface distortion and contamination.Herein,we report the ultrafast and high-efficiency hot electron transfer by creating a novel Au@MoS_(2) core-shell heterostructure with atomically sharp and dramatically enlarged interface.Our femtosecond transient absorption spectroscopy study indicates the hot-electron injection from Au nanoparticles to MoS_(2) in Au@MoS_(2) is within 244 fs,compared with the 493 fs of the mechanically-transferred Au/MoS_(2) control sample.And meanwhile,the injection efficiency is improved from 3.33% of Au/MoS_(2) to 25.3%of our Au@MoS_(2).The results are further proved by Kelvin probe force microscopy and discrete dipolar approximation studies,which provide strong evidences that the improved charge transfer is attributed to the atomic-level clean and fully-encapsulated interface of the product.This study provides fundamental understanding of the intrinsic charge transfer within Au@MoS_(2) heterostructures and thus demonstrates an intriguing material geometry for future plasmonic and optoelectronic devices.
作者
刘然
朱翔宇
刘盛洪
欧阳德才
马小茜
夏芳芳
余一梦
张悍
吴劲松
刘世元
梁文锡
李渊
翟天佑
Ran Liu;Xiangyu Zhu;Shenghong Liu;Decai Ouyang;XiaoXi Ma;Fangfang Xia;Yimeng Yu;Han Zhang;Jinsong Wu;Shiyuan Liu;Wenxi Liang;Yuan Li;Tianyou Zhai(State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Nanostructure Research Center,Wuhan University of Technology,Wuhan 430070,China;School of Engineering and Materials Science,Queen Mary University of London,Mile End Road,London,E14NS,UK;State Key Laboratory of Digital Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Shenzhen Huazhong University of Science and Technology Research Institute,Shenzhen 518057,China)
基金
supported by the Ministry of Science and Technology of China(2021YFA1200501)
the National Natural Science Foundation of China(U22A20137,U21A2069,and 21825103)
Guangdong Basic and Applied Basic Research Foundation(2020A1515110330)
Shenzhen Science and Technology Innovation Program(JCYJ20220818102215033,GJHZ20210705142542015,and JCYJ20220530160811027)
the support from the Queen Mary–HUST Strategic Partner Fund。
