Spatially heterogeneous ultrafast interfacial carrier dynamics of 2D-MoS2 flakes

Liang, Yu1,2,7; Li, Bo-Han1,2,7; Li, Ziling3; Zhang, Guanhua1,2; Sun, Julong1,2; Zhou, Chuanyao1,2; Tao, Youtian4,5; Ye, Yu3; Ren, Zefeng1,2; Yang, Xueming1,2,6

2021-11-01

10.1016/j.mtphys.2021.100506

Materials Today Physics   影响因子和分区

2542-5293

Understanding the ultrafast carrier dynamics of transition metal dichalcogenides is critical for future applications in high-speed electronic and optoelectronic devices. In this work, we used a combination of femtosecond (fs) time-resolved micro-area photoelectron spectroscopy and photoemission electron microscopy (PEEM) to obtain the space-resolved surface photovoltage (SPV) and photoelectron intensity dynamics of two-dimensional (2D) molybdenum disulfide (MoS2) flakes, both of which exhibited high spatial heterogeneity and defect effects. Additionally, surface S vacancy defects were characterized by spatially resolved X-ray photoelectron spectroscopy. The SPV relaxation dynamics indicated that the charge carrier lifetime in the space-charge layer (SCL) ranged from several to tens of nanoseconds and was dominated by the thermionic emission process. The defects, which acted as electron-hole recombination centers, greatly shortened the charge carrier lifetime by almost one order of magnitude. Furthermore, three relaxation processes were observed in the photoelectron intensity dynamics, namely, two fast processes with rates of 3-6 ps (ps) and 60-100 ps, which were largely affected by the defect density, and one slow relaxation process with a rate of 2-5 ns (ns). However, these were not related to the defect density and were attributed to the transportation of electrons towards the bulk. Therefore, our results provide a deeper understanding of the interfacial carrier dynamics of 2D-MoS2 materials and the effects of defects on charge carrier lifetime in the SCL. (C) 2021 Elsevier Ltd. All rights reserved.

PEEM Surface photovoltage Charge carrier recombination Space charge layer Transition metal dichalcogenides

SCI ; EI

英语

其他

Ministry of Science and Technology of China[2018YFA0208700] ; Chinese Academy of Sciences[XDB17000000] ; National Natural Science Foundation of China[22073097,21688102]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied

WOS:000701925300008

ELSEVIER

20220311467263

Carrier lifetime ; Dynamics ; Layered semiconductors ; Molybdenum compounds ; Photoelectrons ; Photons ; Relaxation processes ; Sulfur compounds ; Surface properties ; X ray photoelectron spectroscopy

Metallurgy and Metallography:531 ; Electricity: Basic Concepts and Phenomena:701.1 ; Electromagnetic Waves:711 ; Semiconducting Materials:712.1 ; Mechanics:931.1 ; Physical Properties of Gases, Liquids and Solids:931.2 ; Atomic and Molecular Physics:931.3 ; Materials Science:951

Web of Science

1.Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Mol React Dynam, 457 Zhongshan Rd, Dalian 116023, Liaoning, Peoples R China
2.Chinese Acad Sci, Dalian Inst Chem Phys, Dynam Res Ctr Energy & Environm Mat, 457 Zhongshan Rd, Dalian 116023, Liaoning, Peoples R China
3.Peking Univ, Sch Phys, 5 Yiheyuan Rd, Beijing 100871, Peoples R China
4.Nanjing Tech Univ, Key Lab Flexible Elect KLOFE, 30 South Puzhu Rd, Nanjing 211816, Peoples R China
5.Nanjing Tech Univ, Inst Adv Mat IAM, 30 South Puzhu Rd, Nanjing 211816, Peoples R China
6.Southern Univ Sci & Technol, Dept Chem, 1088 Xueyuan Rd, Shenzhen 518055, Guangdong, Peoples R China
7.Univ Chinese Acad Sci, 19 A Yuquan Rd, Beijing 100049, Peoples R China

Liang, Yu,Li, Bo-Han,Li, Ziling,et al. Spatially heterogeneous ultrafast interfacial carrier dynamics of 2D-MoS2 flakes[J]. Materials Today Physics,2021,21.

Liang, Yu.,Li, Bo-Han.,Li, Ziling.,Zhang, Guanhua.,Sun, Julong.,...&Yang, Xueming.(2021).Spatially heterogeneous ultrafast interfacial carrier dynamics of 2D-MoS2 flakes.Materials Today Physics,21.

Liang, Yu,et al."Spatially heterogeneous ultrafast interfacial carrier dynamics of 2D-MoS2 flakes".Materials Today Physics 21(2021).