Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2

被引：143

作者：

Cabo, Antonija Grubisic ^{[1
]}

Miwa, Jill A. ^{[1
]}

Gronborg, Signe S. ^{[1
]}

Riley, Jonathon M. ^{[2
]}

Johannsen, Jens C. ^{[3
]}

Cacho, Cephise ^{[4
]}

Alexander, Oliver ^{[4
]}

Chapman, Richard T. ^{[4
]}

Springate, Emma ^{[4
]}

Grioni, Marco ^{[3
]}

Lauritsen, Jeppe V. ^{[1
]}

King, Phil D. C. ^{[2
]}

Hofmann, Philip ^{[1
]}

Ulstrup, Soren ^{[1
]}

机构：

[1] Aarhus Univ, Dept Phys & Astron, Interdisciplinary Nanosci Ctr, DK-8000 Aarhus C, Denmark

[2] Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland

[3] Ecole Polytech Fed Lausanne, Inst Condensed Matter Phys, CH-1015 Lausanne, Switzerland

[4] STFC Rutherford Appleton Lab, Cent Laser Facil, Didcot OX11 0QX, Oxon, England

来源：

NANO LETTERS | 2015年 / 15卷 / 09期

基金：

英国生物技术与生命科学研究理事会; 英国工程与自然科学研究理事会; 瑞士国家科学基金会;

关键词：

Transition metal dichalcogenides; MoS2; free carriers; excitons; time- and angle-resolved photoemission spectroscopy; VALLEY POLARIZATION; EXCITONS; RECOMBINATION; TRANSITION; BANDGAP;

D O I：

10.1021/acs.nanolett.5b01967

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for a SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasipartide band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.

引用

页码：5883 / 5887

页数：5

共 34 条

[1] Extraordinary Sunlight Absorption and One Nanometer Thick Photovoltaics Using Two-Dimensional Monolayer Materials
Bernardi, Marco
Palummo, Maurizia
Grossman, Jeffrey C.
[J]. NANO LETTERS, 2013, 13 (08) : 3664 - 3670
[2] Strong Light-Matter Interactions in Heterostructures of Atomically Thin Films
Britnell, L.
Ribeiro, R. M.
Eckmann, A.
Jalil, R.
Belle, B. D.
Mishchenko, A.
Kim, Y. -J.
Gorbachev, R. V.
Georgiou, T.
Morozov, S. V.
Grigorenko, A. N.
Geim, A. K.
Casiraghi, C.
Castro Neto, A. H.
Novoselov, K. S.
[J]. SCIENCE, 2013, 340 (6138) : 1311 - 1314
[3] Ultrafast Charge Separation and Indirect Exciton Formation in a MoS2-MoSe2 van der Waals Heterostructure
Ceballos, Frank
Bellus, Matthew Z.
Chiu, Hsin-Ying
Zhao, Hui
[J]. ACS NANO, 2014, 8 (12) : 12717 - 12724
[4] Single-grating monochromator for extreme-ultraviolet ultrashort pulses
Frassetto, Fabio
Cacho, Cephise
Froud, Chris A.
Turcu, I. C. Edmund
Villoresi, Paolo
Bryan, Will A.
Springate, Emma
Poletto, Luca
[J]. OPTICS EXPRESS, 2011, 19 (20): : 19169 - 19181
[5] Gierz I, 2013, NAT MATER, V12, P1119, DOI [10.1038/NMAT3757, 10.1038/nmat3757]
[6] FREE-CARRIER AND EXCITON RECOMBINATION RADIATION IN GAAS
GILLEO, MA
BAILEY, PT
HILL, DE
[J]. PHYSICAL REVIEW, 1968, 174 (03): : 898 - &
[7] Synthesis of Epitaxial Single-Layer MoS2 on Au(111)
Gronborg, Signe S.
Ulstrup, Soren
Bianchi, Marco
Dendzik, Maciej
Sanders, Charlotte E.
Lauritsen, Jeppe V.
Hofmann, Philip
Miwa, Jill A.
[J]. LANGMUIR, 2015, 31 (35) : 9700 - 9706
[8] Hong XP, 2014, NAT NANOTECHNOL, V9, P682, DOI [10.1038/NNANO.2014.167, 10.1038/nnano.2014.167]
[9] THEORY OF THE CONTRIBUTION OF EXCITONS TO THE COMPLEX DIELECTIC CONSTANT OF CRYSTALS
HOPFIELD, JJ
[J]. PHYSICAL REVIEW, 1958, 112 (05): : 1555 - 1567
[10] Direct View of Hot Carrier Dynamics in Graphene
Johannsen, Jens Christian
Ulstrup, Soren
Cilento, Federico
Crepaldi, Alberto
Zacchigna, Michele
Cacho, Cephise
Turcu, I. C. Edmond
Springate, Emma
Fromm, Felix
Raidel, Christian
Seyller, Thomas
Parmigiani, Fulvio
Grioni, Marco
Hofmann, Philip
[J]. PHYSICAL REVIEW LETTERS, 2013, 111 (02)

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