Van der Waals single-layer materials are characterized by an inherent extremely low bending rigidity and therefore are prone to nanoscale structural modifications due to substrate interactions. Such interactions can induce excess charge concentration, conformational ripples, and residual mechanical strain. In this work, we employed spatially resolved Raman and photoluminescence (PL) images to investigate strain and doping inhomogeneities in a single layer exfoliated molybdenum disulphide crystal. We have found that correlations between the spectral parameters of the most prominent Raman bands A1′ and E′ enable us to decouple and quantify strain and charge doping effects. In comparison with Atomic Force Microscopy (AFM) topography, we show that the spatial distribution of the position of the A− -trion PL peak is strain sensitive and its linewidth can capture features smaller than the laser spot size. The presented optical analysis may have implications in the development of high-quality devices based on two-dimensional materials since structural and electronic modifications affect considerably their carrier mobility and conductivity.
References
1.
K. S.
Novoselov
, A. K.
Geim
, S. V.
Morozov
, D.
Jiang
, Y.
Zhang
, S. V.
Dubonos
, I. V.
Grigorieva
, and A. A.
Firsov
, Science
306
(5696
), 666
(2004
).2.
K. S.
Novoselov
, D.
Jiang
, F.
Schedin
, T. J.
Booth
, V. V.
Khotkevich
, S. V.
Morozov
, and A. K.
Geim
, Proc. Natl. Acad. Sci. U.S.A.
102
(30
), 10451
(2005
).3.
A. K.
Geim
and I. V.
Grigorieva
, Nature
499
(7459
), 419
(2013
).4.
A. C.
Ferrari
, F.
Bonaccorso
, V.
Fal'ko
, K. S.
Novoselov
, S.
Roche
, P.
Boggild
, S.
Borini
, F. H. L.
Koppens
, V.
Palermo
, N.
Pugno
, J. A.
Garrido
, R.
Sordan
, A.
Bianco
, L.
Ballerini
, M.
Prato
, E.
Lidorikis
, J.
Kivioja
, C.
Marinelli
, T.
Ryhanen
, A.
Morpurgo
, J. N.
Coleman
, V.
Nicolosi
, L.
Colombo
, A.
Fert
, M.
Garcia-Hernandez
, A.
Bachtold
, G. F.
Schneider
, F.
Guinea
, C.
Dekker
, M.
Barbone
, Z. P.
Sun
, C.
Galiotis
, A. N.
Grigorenko
, G.
Konstantatos
, A.
Kis
, M.
Katsnelson
, L.
Vandersypen
, A.
Loiseau
, V.
Morandi
, D.
Neumaier
, E.
Treossi
, V.
Pellegrini
, M.
Polini
, A.
Tredicucci
, G. M.
Williams
, B. H.
Hong
, J. H.
Ahn
, J. M.
Kim
, H.
Zirath
, B. J.
van Wees
, H.
van der Zant
, L.
Occhipinti
, A.
Di Matteo
, I. A.
Kinloch
, T.
Seyller
, E.
Quesnel
, X. L.
Feng
, K.
Teo
, N.
Rupesinghe
, P.
Hakonen
, S. R. T.
Neil
, Q.
Tannock
, T.
Lofwandera
, and J.
Kinaret
, Nanoscale
7
(11
), 4598
(2015
).5.
R.
Coehoorn
, C.
Haas
, and R. A.
de Groot
, Phys. Rev. B
35
(12
), 6203
(1987
).6.
R.
Coehoorn
, C.
Haas
, J.
Dijkstra
, C. J.
Flipse
, R. A.
de Groot
, and A.
Wold
, Phys. Rev. B
35
(12
), 6195
(1987
).7.
K. F.
Mak
, C.
Lee
, J.
Hone
, J.
Shan
, and T. F.
Heinz
, Phys. Rev. Lett.
105
(13
), 136805
(2010
).8.
S.
Lebègue
and O.
Eriksson
, Phys. Rev. B
79
(11
), 115409
(2009
).9.
B.
Radisavljevic
, M. B.
Whitwick
, and A.
Kis
, ACS Nano
5
(12
), 9934
(2011
).10.
B.
Radisavljevic
, A.
Radenovic
, J.
Brivio
, V.
Giacometti
, and A.
Kis
, Nat. Nanotechnol.
6
(3
), 147
(2011
).11.
S.
Bertolazzi
, J.
Brivio
, and A.
Kis
, ACS Nano
5
(12
), 9703
(2011
).12.
H. J.
Conley
, B.
Wang
, J. I.
Ziegler
, R. F.
Haglund
, S. T.
Pantelides
, and K. I.
Bolotin
, Nano Lett.
13
(8
), 3626
(2013
).13.
E.
Scalise
, M.
Houssa
, G.
Pourtois
, V.
Afanas'ev
, and A.
Stesmans
, Nano Res.
5
(1
), 43
(2012
).14.
G.
Anagnostopoulos
, C.
Androulidakis
, E. N.
Koukaras
, G.
Tsoukleri
, I.
Polyzos
, J.
Parthenios
, K.
Papagelis
, and C.
Galiotis
, ACS Appl. Mater. Interfaces
7
(7
), 4216
(2015
).15.
M. S.
Bronsgeest
, N.
Bendiab
, S.
Mathur
, A.
Kimouche
, H. T.
Johnson
, J.
Coraux
, and P.
Pochet
, Nano Lett.
15
(8
), 5098
(2015
).16.
Z.
Li
, I. A.
Kinloch
, R. J.
Young
, K. S.
Novoselov
, G.
Anagnostopoulos
, J.
Parthenios
, C.
Galiotis
, K.
Papagelis
, C. Y.
Lu
, and L.
Britnell
, ACS Nano
9
(4
), 3917
(2015
).17.
O.
Frank
, J.
Vejpravova
, V.
Holy
, L.
Kavan
, and M.
Kalbac
, Carbon
68
, 440
(2014
).18.
C.
Rice
, R. J.
Young
, R.
Zan
, U.
Bangert
, D.
Wolverson
, T.
Georgiou
, R.
Jalil
, and K. S.
Novoselov
, Phys. Rev. B
87
(8
), 081307(R)
(2013
).19.
Y. L.
Wang
, C. X.
Cong
, C. Y.
Qiu
, and T.
Yu
, Small
9
(17
), 2857
(2013
).20.
E.
Scalise
, M.
Houssa
, G.
Pourtois
, V. V.
Afanas′ev
, and A.
Stesmans
, Physica E
56
, 416
(2014
).21.
Y.
Cai
, J.
Lan
, G.
Zhang
, and Y. W.
Zhang
, Phys. Rev. B
89
(3
), 035438
(2014
).22.
B.
Chakraborty
, A.
Bera
, D. V. S.
Muthu
, S.
Bhowmick
, U. V.
Waghmare
, and A. K.
Sood
, Phys. Rev. B
85
(16
), 161403
(2012
).23.
A.
Tarasov
, S. Y.
Zhang
, M. Y.
Tsai
, P. M.
Campbell
, S.
Graham
, S.
Barlow
, S. R.
Marder
, and E. M.
Vogel
, Adv. Mater.
27
(7
), 1175
(2015
).24.
H. Y.
Park
, S. R.
Dugasani
, D. H.
Kang
, J.
Jeon
, S. K.
Jang
, S.
Lee
, Y.
Roh
, S. H.
Park
, and J. H.
Park
, ACS Nano
8
(11
), 11603
(2014
).25.
X. X.
Wei
, Z. H.
Yu
, F. R.
Hu
, Y.
Cheng
, L. W.
Yu
, X. Y.
Wang
, M.
Xiao
, J. Z.
Wang
, X. R.
Wang
, and Y.
Shi
, AIP Adv.
4
(12
), 123004
(2014
).26.
See supplementary material at http://dx.doi.org/10.1063/1.4948357 for literature data regarding the effect of uniaxial strain on characteristic Raman modes and optical transition of MoS2, the spectral accuracy of the spectrometer, the laser beam spot-size determination as well as Raman modes and spectra of MoS2, the evolution of the Raman spectra near bulk-monolayer border, the A1′ linewidth map, the A1′ and E′ Raman modes frequency position correlation, details on the optical separation of doping and strain in SL-MoS2, the application of the proposed method to other samples, characteristic PL spectra and maps, details on the method used to locate the MoS2 flake borders, the PL emission energy at the edges of SL-MoS2.
27.
N.
Bonini
, M.
Lazzeri
, N.
Marzari
, and F.
Mauri
, Phys. Rev. Lett.
99
(17
), 176802
(2007
).28.
J. E.
Lee
, G.
Ahn
, J.
Shim
, Y. S.
Lee
, and S.
Ryu
, Nat Commun.
3
, 1024
(2012
).29.
C.
Neumann
, S.
Reichardt
, P.
Venezuela
, M.
Drogeler
, L.
Banszerus
, M.
Schmitz
, K.
Watanabe
, T.
Taniguchi
, F.
Mauri
, B.
Beschoten
, S. V.
Rotkin
, and C.
Stampfer
, Nat. Commun.
6
, 8429
(2015
).30.
C.
Ulrich
, E.
Anastassakis
, K.
Syassen
, A.
Debernardi
, and M.
Cardona
, Phys. Rev. Lett.
78
(7
), 1283
(1997
).31.
C.
Lee
, H.
Yan
, L. E.
Brus
, T. F.
Heinz
, J.
Hone
, and S.
Ryu
, ACS Nano
4
(5
), 2695
(2010
).32.
J.
Zabel
, R. R.
Nair
, A.
Ott
, T.
Georgiou
, A. K.
Geim
, K. S.
Novoselov
, and C.
Casiraghi
, Nano Lett.
12
(2
), 617
(2012
).33.
K. F.
Mak
, K.
He
, C.
Lee
, G. H.
Lee
, J.
Hone
, T. F.
Heinz
, and J.
Shan
, Nat. Mater.
12
(3
), 207
(2013
).34.
N.
Scheuschner
, O.
Ochedowski
, A.-M.
Kaulitz
, R.
Gillen
, M.
Schleberger
, and J.
Maultzsch
, Phys. Rev. B
89
(12
), 125406
(2014
).35.
A.
Splendiani
, L.
Sun
, Y.
Zhang
, T.
Li
, J.
Kim
, C. Y.
Chim
, G.
Galli
, and F.
Wang
, Nano Lett.
10
(4
), 1271
(2010
).36.
A.
Castellanos-Gomez
, R.
Roldán
, E.
Cappelluti
, M.
Buscema
, F.
Guinea
, H. S. J.
van der Zant
, and G. A.
Steele
, Nano Lett.
13
(11
), 5361
(2013
).37.
P.
Johari
and V. B.
Shenoy
, ACS Nano
6
(6
), 5449
(2012
).38.
A.
Kumar
and P. K.
Ahluwalia
, Phys. B: Condens. Matter
419
, 66
(2013
).39.
H.
Peelaers
and C. G.
Van de Walle
, Phys. Rev. B
86
(24
), 241401(R)
(2012
).40.
W. S.
Yun
, S. W.
Han
, S. C.
Hong
, I. G.
Kim
, and J. D.
Lee
, Phys. Rev. B
85
(3
), 033305
(2012
).41.
H.
Shi
, H.
Pan
, Y. W.
Zhang
, and B. I.
Yakobson
, Phys. Rev. B
87
(15
), 155304
(2013
).42.
H. R.
Gutiérrez
, N.
Perea-López
, A. L.
Elías
, A.
Berkdemir
, B.
Wang
, R.
Lv
, F.
López-Urías
, V. H.
Crespi
, H.
Terrones
, and M.
Terrones
, Nano Lett.
13
(8
), 3447
(2013
).43.
J.
Feng
, X.
Qian
, C. W.
Huang
, and J.
Li
, Nat. Photonics
6
(12
), 866
(2012
).© 2016 Author(s).
2016
Author(s)
You do not currently have access to this content.
