We present electronic transport measurements on etched graphene nanoribbons on silicon dioxide before and after a short hydrofluoric acid (HF) treatment. We report on changes in the transport properties, in particular, in terms of a decreasing transport gap and a reduced doping level after HF dipping. Interestingly, the effective energy gap is nearly unaffected by the HF treatment. Additional measurements on a graphene nanoribbon with lateral graphene gates support strong indications that the HF significantly modifies the edges of the investigated nanoribbons leading to a significantly reduced disorder potential in these graphene nanostructures.
REFERENCES
1.
Z.
Chen
, Y.-M.
Lin
, M.
Rooks
, and P.
Avouris
, Physica E
40
, 228
(2007
).2.
M. Y.
Han
, B.
Özyilmaz
, Y.
Zhang
, and P.
Kim
, Phys. Rev. Lett.
98
, 206805
(2007
).3.
X.
Li
, X.
Wang
, L.
Zhang
, S.
Lee
, and H.
Dai
, Science
319
, 1229
(2008
).4.
X.
Wang
, Y.
Ouyang
, X.
Li
, H.
Wang
, J.
Guo
, and H.
Dai
, Phys. Rev. Lett.
100
, 206803
(2008
).5.
F.
Molitor
, A.
Jacobsen
, C.
Stampfer
, J.
Güttinger
, T.
Ihn
, and K.
Ensslin
, Phys. Rev. B
79
, 075426
(2009
).6.
C.
Stampfer
, J.
Güttinger
, S.
Hellmüller
, F.
Molitor
, K.
Ensslin
, and T.
Ihn
, Phys. Rev. Lett.
102
, 056403
(2009
).7.
K.
Todd
, H.-T.
Chou
, S.
Amasha
, and D.
Goldhaber-Gordon
, Nano Lett.
9
, 416
(2009
).8.
X. L.
Liu
, J. B.
Oostinga
, A. F.
Morpurgo
, and L. M. K.
Vandersypen
, Phys. Rev. B
80
, 121407
(2009
).9.
F.
Molitor
, C.
Stampfer
, J.
Güttinger
, A.
Jacobsen
, T.
Ihn
, and K.
Ensslin
, Semicond. Sci. Technol.
25
, 034002
(2010
).10.
P.
Gallagher
, K.
Todd
, and D.
Goldhaber-Gordon
, Phys. Rev. B
81
, 115409
(2010
).11.
M. Y.
Han
, J. C.
Brant
, and P.
Kim
, Phys. Rev. Lett.
104
, 056801
(2010
).12.
B.
Terrés
, J.
Dauber
, C.
Volk
, S.
Trellenkamp
, U.
Wichmann
, and C.
Stampfer
, Appl. Phys. Lett.
98
, 032109
(2011
).13.
J. B.
Oostinga
, B.
Sacépé
, M. F.
Craciun
, and A. F.
Morpurgo
, Phys. Rev. B
81
, 193408
(2010
).14.
C. R.
Dean
, A. F.
Young
, I.
Meric
, C.
Lee
, L.
Wang
, S.
Sorgenfrei
, K.
Watanabe
, T.
Taniguchi
, P.
Kim
, K. L.
Shepard
, and J.
Hone
, Nat. Nanotechnol.
5
, 722
(2010
).15.
J.
Xue
, J.
Sanchez-Yamagishi
, D.
Bulmash
, P.
Jacquod
, A.
Deshpande
, K.
Watanabe
, T.
Taniguchi
, P.
Jarillo-Herrero
, and B. J.
LeRoy
, Nature Mater.
10
, 282
–285
(2011
).16.
F.
Forster
, A.
Molina-Sanchez
, S.
Engels
, A.
Epping
, K.
Watanabe
, T.
Taniguchi
, L.
Wirtz
, and C.
Stampfer
, Phys. Rev. B
88
, 085419
(2013
)17.
D.
Bischoff
, T.
Krähenmann
, S.
Dröscher
, M. A.
Gruner
, C.
Barraud
, T.
Ihn
, and K.
Ensslin
, Appl. Phys. Lett.
101
, 203103
(2012
).18.
S.
Engels
, A.
Epping
, C.
Volk
, S.
Korte
, B.
Voigtländer
, K.
Watanabe
, T.
Taniguchi
, S.
Trellenkamp
, and C.
Stampfer
, Appl. Phys. Lett.
103
, 073113
(2013
).19.
N.
Tombros
, A.
Veligura
, J.
Junesch
, M. H. D.
Guimaraes
, I. J.
Vera-Marun
, H. T.
Jonkman
, and B. J.
van Wees
, Nat. Phys.
7
, 697
(2011
).20.
D.-K.
Ki
and A. F.
Morpurgo
, Phys. Rev. Lett.
108
, 266601
(2012
).21.
X.
Wang
, Y.
Ouyang
, L.
Jiao
, H.
Wang
, L.
Xie
, J.
Wu
, J.
Guo
, and H.
Dai
, Nat. Nanotechnol.
6
, 563
(2011
).22.
A. C.
Ferrari
, J. C.
Meyer
, V.
Scardaci
, C.
Casiraghi
, M.
Lazzeri
, F.
Mauri
, S.
Piscanec
, D.
Jiang
, K. S.
Novoselov
, S.
Roth
, and A. K.
Geim
, Phys. Rev. Lett.
97
, 187401
(2006
);
[PubMed]
D.
Graf
, F.
Molitor
, K.
Ensslin
, C.
Stampfer
, A.
Jungen
, C.
Hierold
, and L.
Wirtz
, Nano Lett.
7
, 238
(2007
).
[PubMed]
23.
Here, we follow Molitor et al.9 For extracting the transport gap, the data are smoothed with a running average over 0.5 V in and the regions with a linear increase in conductance next to the transport gap are fitted with a linear slope. From the intersection of these two (right and left) lines with G = 0, we obtain Vr and Vl and extract the size of the transport gap and the position of the charge neutrality point . For the effective energy gap, the size of the largest Coulomb diamond like feature in a plot of dI/dV as a function of bias and back gate voltage is estimated.
24.
This also confirms that our GNRs are not suspended; when fully suspending individual nanoribbons we found .
25.
F.
Sols
, F.
Guinea
, and A. H.
Castro-Neto
, Phys. Rev. Lett.
99
, 166803
(2007
).26.
In Ref. 9, the following values for a and b have been found: and .
27.
X.
Du
, I.
Skachko
, A.
Barker
, and E. Y.
Andrei
, Nat. Nanotechnol.
3
, 491
(2008
).28.
K. I.
Bolotin
, K. J.
Sikes
, Z.
Jiang
, M.
Klima
, G.
Fudenberg
, J.
Hone
, P.
Kim
, and H. L.
Stormer
, Solid State Commun.
146
, 351
(2008
).29.
The estimated values are and .
30.
H.
Tachikawa
, T.
Iyama
, and H.
Kawabata
, Jpn. J. Appl. Phys., Part 1
49
, 01AH02
(2010
).31.
S.
Ihnatsenka
and G.
Kirczenow
, Phys. Rev. B
83
, 245442
(2011
).32.
H.
Zheng
and W.
Duley
, Phys. Rev. B
78
, 045421
(2008
).© 2014 AIP Publishing LLC.
2014
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