We find negative differential resistance (NDR) at room temperature in ultrathin films of nickel (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine [NiPc(OBu)8] deposited on highly ordered pyrolytic graphite (HOPG) substrate [NiPc(OBu)8/HOPG] and NiPc(OBu)8 on graphene oxide (GO) deposited on HOPG [NiPc(OBu)8/GO/HOPG]. For the NiPc(OBu)8/HOPG system, NiPc(OBu)8 was transferred four times onto HOPG by the Langmuir-Blodgett (LB) technique. We have prepared a stable Langmuir monolayer of amphiphilic GO at the air-water interface and transferred it onto HOPG by the LB technique. Further, the monolayer of NiPc(OBu)8 was transferred four times for good coverage on GO to obtain the NiPc(OBu)8/GO/HOPG system. The current-voltage characteristics were carried out using a current sensing atomic force microscope (CSAFM) with a platinum (Pt) tip that forms Pt/NiPc(OBu)8/HOPG and Pt/NiPc(OBu)8/GO/HOPG junctions. The CSAFM, UV-visible spectroscopy, and cyclic voltammetry studies show that the NDR effect occurs due to molecular resonant tunneling. In the Pt/NiPc(OBu)8/GO/HOPG junction, we find that due to the presence of GO, the features of NDR become more prominent. Also, GO causes a shift in NDR voltage towards a lower value in the negative bias direction. We attribute this behavior to the role of GO in injecting holes into the NiPc(OBu)8 film.

1.
Z. J.
Donhauser
,
B. A.
Mantooth
,
K. F.
Kelly
,
L. A.
Bumm
,
J. D.
Monnell
,
J. J.
Stapleton
,
D. W.
Price
,
A. M.
Rawlett
,
D. L.
Allara
,
J. M.
Tour
, and
P. S.
Weiss
,
Science
292
,
2303
(
2001
).
2.
J.
Shao
,
X. Y.
Zhang
,
Y.
Zheng
,
B.
Wang
, and
Y.
Chen
,
RSC Adv.
5
,
13917
(
2015
).
3.
G.
Yang
,
C. H.
Jia
,
Y. H.
Chen
,
X.
Chen
, and
W. F.
Zhang
,
J. Appl. Phys.
115
,
204515
(
2014
).
4.
H.
Kim
,
S. S.
Jang
,
R. A.
Kiehl
, and
W. A.
Goddard
,
J. Phys. Chem. C
115
,
3722
(
2011
).
5.
H.
Ren
,
G.
Zhang
,
N.
Lin
,
L.
Deng
,
Y.
Luo
, and
F.
Huang
,
Phys. Chem. Chem. Phys.
18
,
26586
(
2016
).
6.
Y.
Majima
,
D.
Ogawa
,
M.
Iwamoto
,
Y.
Azuma
,
E.
Tsurumaki
, and
A.
Osuka
,
J. Am. Chem. Soc.
135
,
14159
(
2013
).
8.
Y.
Zhu
,
H.
Wang
,
W.
Chen
,
Y.
Wang
, and
D.
Yan
,
Org. Electron.
35
,
24
(
2016
).
9.
N. S.
John
,
S. K.
Pati
, and
G. U.
Kulkarni
,
Appl. Phys. Lett.
92
,
013120
(
2008
).
10.
G.
Balakrishnan
,
A. V.
Soldatova
,
P. J.
Reid
, and
T. G.
Spiro
,
J. Am. Chem. Soc.
136
,
8746
(
2014
).
11.
T. S.
Harish
and
P.
Viswanath
,
Thin Solid Films
598
,
170
(
2016
).
12.
T. C.
Gunaratne
,
A. V.
Gusev
,
X.
Peng
,
A.
Rosa
,
G.
Ricciardi
,
E. J.
Baerends
,
C.
Rizzoli
,
M. E.
Kenney
, and
M. A. J.
Rodgers
,
J. Phys. Chem. A
109
,
2078
(
2005
).
13.
J. H.
Yang
,
Y.
Gao
,
W.
Zhang
,
P.
Tang
,
J.
Tan
,
A. H.
Lu
, and
D.
Ma
,
J. Phys. Chem. C
117
,
3785
(
2013
).
14.
X.
Zhang
,
Y.
Feng
,
S.
Tang
, and
W.
Feng
,
Carbon
48
,
211
(
2010
).
15.
U.
Mazur
and
K. W.
Hipps
,
J. Phys. Chem.
98
,
8169
(
1994
).
16.
P.
Järvinen
,
S. K.
Hämäläinen
,
M.
Ijäs
,
A.
Harju
, and
P.
Liljeroth
,
J. Phys. Chem. C
118
,
13320
(
2014
).
17.
A.
Nayak
and
K. A.
Suresh
,
Phys. Rev. E
78
,
021606
(
2008
).
18.
H. N.
Gayathri
and
K. A.
Suresh
,
J. Appl. Phys.
117
,
245311
(
2015
).
19.
K. A.
Suresh
and
H. N.
Gayathri
,
Mol. Cryst. Liq. Cryst.
646
,
194
(
2017
).
20.
R. C.
Stan
,
A.
Kros
,
J.
Appel
, and
N. J. M.
Sanghamitra
,
J. Phys. Chem. C
120
,
7639
(
2016
).
21.
L. J.
Wei
,
Y.
Yuan
,
J.
Wang
,
H. Q.
Tu
,
Y.
Gao
,
B.
You
, and
J.
Du
,
Phys. Chem. Chem. Phys.
19
,
11864
(
2017
).
22.
Y.
Cai
,
Q.
Yuan
,
Y.
Ye
,
J.
Liu
, and
C.
Liang
,
Phys. Chem. Chem. Phys.
18
,
17440
(
2016
).
23.
L. J.
Cote
,
F.
Kim
, and
J.
Huang
,
J. Am. Chem. Soc.
131
,
1043
(
2009
).
24.
J.
Kim
,
L. J.
Cote
,
F.
Kim
,
W.
Yuan
,
K. R.
Shull
, and
J.
Huang
,
J. Am. Chem. Soc.
132
,
8180
(
2010
).
25.
L. J.
Cote
,
J.
Kim
,
Z.
Zhang
,
C.
Sun
, and
J.
Huang
,
Soft Matter
6
,
6096
(
2010
).
26.
T.
Wang
,
T. R.
Kafle
,
B.
Kattel
,
Q.
Liu
,
J.
Wu
, and
W. L.
Chan
,
Sci. Rep.
6
,
28895
(
2016
).
27.
K.
Xiao
,
W.
Deng
,
J. K.
Keum
,
M.
Yoon
,
I. V.
Vlassiouk
,
K. W.
Clark
,
A. P.
Li
,
I. I.
Kravchenko
,
G.
Gu
,
E. A.
Payzant
,
B. G.
Sumpter
,
S. C.
Smith
,
J. F.
Browning
, and
D. B.
Geohegan
,
J. Am. Chem. Soc.
135
,
3680
(
2013
).
28.
C. C. B.
Bufon
,
C.
Vervacke
,
D. J.
Thurmer
,
M.
Fronk
,
G.
Salvan
,
S.
Lindner
,
M.
Knupfer
,
D. R. T.
Zahn
, and
O. G.
Schmidt
,
J. Phys. Chem. C
118
,
7272
(
2014
).
29.
H. N.
Gayathri
,
B.
Kumar
,
K. A.
Suresh
,
H. K.
Bisoyi
, and
S.
Kumar
,
Phys. Chem. Chem. Phys.
18
,
12101
(
2016
).
30.
Y.
Wang
,
J.
Kröger
,
R.
Berndt
, and
W. A.
Hofer
,
J. Am. Chem. Soc.
131
,
3639
(
2009
).
31.
M.
Toader
,
M.
Knupfer
,
D. R. T.
Zahn
, and
M.
Hietschold
,
J. Am. Chem. Soc.
133
,
5538
(
2011
).
32.
T.
Ceyhan
,
A.
Altındal
,
A. R.
Özkaya
,
Ö.
Çelikbıçak
,
B.
Salih
,
M. K.
Erbil
, and
Ö.
Bekaroğlu
,
Polyhedron
26
,
4239
(
2007
).
33.
H.
Engelkamp
and
R. J. M.
Nolte
,
J. Porphyrins Phthalocyanines
4
,
454
(
2000
).
34.
I.
Seguy
,
P.
Jolinat
,
P.
Destruel
, and
J.
Farenc
,
J. Appl. Phys.
89
,
5442
(
2001
).
35.
T. G.
Gopakumar
,
J.
Meiss
,
D.
Pouladsaz
, and
M.
Hietschold
,
J. Phys. Chem. C
112
,
2529
(
2008
).
36.
D.
Baran
,
A.
Balan
,
S.
Celebi
,
B. M.
Esteban
,
H.
Neugebauer
,
N. S.
Sariciftci
, and
L.
Toppare
,
Chem. Mater.
22
,
2978
(
2010
).
37.
S. J.
Molen
and
P.
Liljeroth
,
J. Phys. Condens. Matter
22
,
133001
(
2010
).
38.
M. A.
Khan
,
S.
Rathi
,
I.
Lee
,
L.
Li
,
D.
Lim
,
M.
Kang
, and
G. H.
Kim
,
Appl. Phys. Lett.
108
,
093104
(
2016
).
39.
S.
Yavuz
,
C.
Kuru
,
D.
Choi
,
A.
Kargar
,
S.
Jin
, and
P. R.
Bandaru
,
Nanoscale
8
,
6473
(
2016
).
40.
B.
Xu
and
Y.
Dubi
,
J. Phys. Condens. Matter
27
,
263202
(
2015
).
41.
N.
Dwivedi
,
R.
McIntosh
,
C.
Dhand
,
S.
Kumar
,
H. K.
Malik
, and
S.
Bhattacharyya
,
ACS Appl. Mater. Interfaces
7
,
20726
(
2015
).

Supplementary Material

You do not currently have access to this content.