Microscopic pump-probe optical technique to characterize the defect of monolayer transition metal dichalcogenides  

作　　者：Ying Yu Xiankun Zhang Zhangkai Zhou Zheng Zhang Yanjun Bao Haofei Xu Limin Lin Yue Zhang Xuehua Wang 

机构地区：[1]State Key Laboratory of Optoelectronic Materials and Technologies,School of Physics,Sun Yat-sen University, Guangzhou 510275,China [2]State Key Laboratory for Advanced Metals and Materials, Beijing Municipal Key Laboratory for Advanced Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

出　　处：《Photonics Research》2019年第7期26-36,共11页光子学研究（英文版）

基　　金：Ministry of Science and Technology of China(2016YFA0301300);National Natural Science Foundation of China(NSFC)(51527802,51602020,11334015,11364001,11504050,11804408,61675237);Guangdong Natural Science Funds for Distinguished Young Scholars(2017B030306007);Guangdong Special Support Program(2017TQ04C487);Natural Science Foundation of Guangdong Province(2016A030312012,2018A030313333);Pearl River ST Nova Program of Guangzhou(201806010033);Guangzhou Science and Technology Projects(201607020023,201805010004)

摘　　要：Monolayer transition metal dichalcogenides(TMDs)are ideal materials for atomically thin,flexible optoelec.tronic and catalytic devices.However,their optoelectrical performance such as quantum yield and carrier mobility often shows below theoretical expectations due to the existence of defects.For monolayer TMD-based devices,finding a low-cost,time-efficient, and nondestructive technique to visualize the change of defect distribution in the space domain and the defect-induced change of the carrier's lifetime is vital for optimizing their optoelectronic properties.Here, we propose a microscopic pump-probe technique to map the defect distribution of monolayer TMDs.It is found that there is a linear relationship between transient differential reflection intensity and defect density,suggesting that this technique not only realizes the visualization of the defect distribution but also achieves the quantitative estimation of defect density.Moreover,the carrier lifetime at each point can also be obtained by the technique. The technique used here provides a new route to characterize the defect of monolayer TMDs on the micro-zone, which will hopefiilly guide the fabrication of high-quality two-dimensional (2D) materials and the promotion of optoelectrical performance.Monolayer transition metal dichalcogenides(TMDs) are ideal materials for atomically thin, flexible optoelectronic and catalytic devices. However, their optoelectrical performance such as quantum yield and carrier mobility often shows below theoretical expectations due to the existence of defects. For monolayer TMD-based devices,finding a low-cost, time-efficient, and nondestructive technique to visualize the change of defect distribution in the space domain and the defect-induced change of the carrier’s lifetime is vital for optimizing their optoelectronic properties. Here, we propose a microscopic pump-probe technique to map the defect distribution of monolayer TMDs. It is found that there is a linear relationship between transient differential reflection intensity and defect density, suggesting that this technique not only realizes the visualization of the defect distribution but also achieves the quantitative estimation of defect density. Moreover, the carrier lifetime at each point can also be obtained by the technique. The technique used here provides a new route to characterize the defect of monolayer TMDs on the micro-zone, which will hopefully guide the fabrication of high-quality two-dimensional(2D) materials and the promotion of optoelectrical performance.

关 键 词：TECHNIQUE MONOLAYER FABRICATION 

分 类 号：O4[理学—物理]