Defect-induced distinct exciton-exciton interactions in WS2 monolayers

作     者：Weihao Zheng Peng Fan Danliang Zhang Biyuang Zheng Cuihuan Ge Ying Chen Boyi Xu Zilan Tang Jianwu Liu Tian Zhang Ying Jiang Xiao Wang Xiaoli Zhu Shula Chen Quan Yuan Anlian Pan 郑玮豪;范鹏;张丹亮;郑弼元;葛翠环;陈荧;徐博一;唐梓岚;刘建武;张添;蒋英;王笑;朱晓莉;陈舒拉;袁荃;潘安练

作者机构：Key Laboratory for Micro-Nano Physics and Technology of Hunan ProvinceState Key Laboratory of Chemo/Biosensing and Chemometriscs and College of Materials Science and EngineeringHunan UniversityChangsha 410082China School of Physics and ElectronicsHunan UniversityChangsha 410082China Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan 430074China Molecular Science and Biomedicine Laboratory(MBL)Institute of Chemical Biology and NanomedicineState Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China 

出 版 物：《Science China Materials》 (中国科学（材料科学（英文版）)

年 卷 期：2022年第65卷第9期

页      面：2502-2510页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：financially supported by the National Natural Science Foundation of China(52002125,U19A2090,62090035,51972105,61905071,and 52172140) China Postdoctoral Science Foundation(2020M672479 and 2020M680112) the Natural Science Foundation of Hunan Province(2021JJ40102 and 2021JJ30132) the Key Program of Science and Technology Department of Hunan Province(2019XK2001 and2020XK2001) the Science and Technology Innovation Program of Hunan Province(2020RC2028) the International Science and Technology Innovation Cooperation Base of Hunan Province(2018WK404) the Open Project Program of Wuhan National Laboratory for Optoelectronics(2020WNLOKF002) 

主　　题：transition metal dichalcogenides monolayers defect population exciton diffusion exciton-exciton annihilation 

摘      要：The optoelectronic properties of atomically thin transition metal dichalcogenides(TMDs)are largely influenced by defect populations(DPs).In this work,we fabricate WSmonolayers with different DPs by varying the fabrication methods and further reveal their distinct exciton-exciton ***-state photoluminescence(PL)experiments show that the monolayer with the lowest DP shows optimal PL intensity at low excitation power;however,it is overtaken and significantly surpassed by monolayers with higher DPs at high excitation ***-power-dependent experiments demonstrate that these monolayers exhibit distinct PL saturation behaviors with the threshold power differing by four orders of *** with in situ PL imaging and time-resolved PL experiments,we attribute such PL evolution discrepancies to the different DPs within these monolayers,which largely influence the exciton diffusion behavior and subsequently bring about distinct nonradiative exciton-exciton annihilations(EEAs).Valley polarization experiments are further employed to re-examine the DPs of these *** work reveals the distinct PL behaviors and underlying exciton dynamics in TMD monolayers with different DPs,which can largely facilitate the engineering of relevant high-performance devices for practical applications.