Spatiotemporal dynamics of excitons in monolayer and bulk WS2

被引：74

作者：

He, Jiaqi ^{[1
,2
]}

He, Dawei ^{[1
]}

Wang, Yongsheng ^{[1
]}

Cui, Qiannan ^{[2
]}

Ceballos, Frank ^{[2
]}

Zhao, Hui ^{[2
]}

机构：

[1] Beijing Jiaotong Univ, Inst Optoelect Technol, Minist Educ, Key Lab Luminescence & Opt Informat, Beijing 100044, Peoples R China

[2] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA

来源：

NANOSCALE | 2015年 / 7卷 / 21期

基金：

美国国家科学基金会;

关键词：

FEW-LAYER MOS2; SINGLE-LAYER; EXFOLIATION; MONO; FABRICATION; TRANSISTORS; DISULFIDE; TRANSPORT; GROWTH; SCALE;

D O I：

10.1039/c5nr00188a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Spatiotemporal dynamics of excitons in monolayer and bulk WS2 at room temperature is studied by transient absorption microscopy in the reflection geometry. Excitons are formed from photocarriers injected by a tightly focused 390 nm pump pulse, and monitored by detecting different reflection of a time-delayed and spatially scanned 620 nm probe pulse. We obtain exciton lifetimes of 22 +/- 1 and 110 +/- 10 ps in monolayer and bulk WS2, respectively. Both lifetimes are independent of the exciton density, showing the absence of multi-exciton recombination processes. Exciton diffusion coefficients of 60 +/- 20 and 3.5 +/- 0.5 cm(2) s(-1) are obtained in monolayer and bulk samples, respectively. These results provide a foundation for understanding excitons in this new material and its optoelectronic applications.

引用

页码：9526 / 9531

页数：6

共 54 条

[11] A WS2 nanosheet based sensing platform for highly sensitive detection of T4 polynucleotide kinase and its inhibitors [J].

Ge, Jia ;

Tang, Li-Juan ;

Xi, Qiang ;

Li, Xi-Ping ;

Yu, Ru-Qin ;

Jiang, Jian-Hui ;

Chu, Xia .

NANOSCALE, 2014, 6 (12) :6866-6872

[12] Coherent Longitudinal Acoustic Phonon Approaching THz Frequency in Multilayer Molybdenum Disulphide [J].

Ge, Shaofeng ;

Liu, Xuefeng ;

Qiao, Xiaofen ;

Wang, Qinsheng ;

Xu, Zhen ;

Qiu, Jun ;

Tan, Ping-Heng ;

Zhao, Jimin ;

Sun, Dong .

SCIENTIFIC REPORTS, 2014, 4

[13] Structures of exfoliated single layers of WS2, MoS2, and MoSe2 in aqueous suspension -: art. no. 125407 [J].

Gordon, RA ;

Yang, D ;

Crozier, ED ;

Jiang, DT ;

Frindt, RF .

PHYSICAL REVIEW B, 2002, 65 (12) :1254071-1254079

[14] Extraordinary Room-Temperature Photoluminescence in Triangular WS2 Monolayers [J].

Gutierrez, Humberto R. ;

Perea-Lopez, Nestor ;

Elias, Ana Laura ;

Berkdemir, Ayse ;

Wang, Bei ;

Lv, Ruitao ;

Lopez-Urias, Florentino ;

Crespi, Vincent H. ;

Terrones, Humberto ;

Terrones, Mauricio .

NANO LETTERS, 2013, 13 (08) :3447-3454

[15] Photoresponsive and Gas Sensing Field-Effect Transistors based on Multilayer WS2 Nanoflakes [J].

Huo, Nengjie ;

Yang, Shengxue ;

Wei, Zhongming ;

Li, Shu-Shen ;

Xia, Jian-Bai ;

Li, Jingbo .

SCIENTIFIC REPORTS, 2014, 4

[16] Transistors with chemically synthesized layered semiconductor WS2 exhibiting 105 room temperature modulation and ambipolar behavior [J].

Hwang, Wan Sik ;

Remskar, Maja ;

Yan, Rusen ;

Protasenko, Vladimir ;

Tahy, Kristof ;

Chae, Soo Doo ;

Zhao, Pei ;

Konar, Aniruddha ;

Xing, Huili ;

Seabaugh, Alan ;

Jena, Debdeep .

APPLIED PHYSICS LETTERS, 2012, 101 (01)

[17] Intrinsic transport properties of electrons and holes in monolayer transition-metal dichalcogenides [J].

Jin, Zhenghe ;

Li, Xiaodong ;

Mullen, Jeffrey T. ;

Kim, Ki Wook .

PHYSICAL REVIEW B, 2014, 90 (04)

[18] Mono- and Bilayer WS2 Light-Emitting Transistors [J].

Jo, Sanghyun ;

Ubrig, Nicolas ;

Berger, Helmuth ;

Kuzmenko, Alexey B. ;

Morpurgo, Alberto F. .

NANO LETTERS, 2014, 14 (04) :2019-2025

[19] Exciton-exciton annihilation in MoSe2 monolayers [J].

Kumar, Nardeep ;

Cui, Qiannan ;

Ceballos, Frank ;

He, Dawei ;

Wang, Yongsheng ;

Zhao, Hui .

PHYSICAL REVIEW B, 2014, 89 (12)

[20] High-performance photocurrent generation from two-dimensional WS2 field-effect transistors [J].

Lee, Seung Hwan ;

Lee, Daeyeong ;

Hwang, Wan Sik ;

Hwang, Euyheon ;

Jena, Debdeep ;

Yoo, Won Jong .

APPLIED PHYSICS LETTERS, 2014, 104 (19)

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