Ultraviolet photoelectron spectroscopy was used to investigate neutral methyl viologen (1,1-dimethyl-1H,1H-[4,4]bipyridinylidene, MV0) deposited on Au(111). As a result of molecule-to-metal electron transfer, the work function of Au(111) was decreased from 5.50to3.30eV. The energy levels of electron transport layers deposited on top of modified Au surfaces were shifted to higher binding energies compared to layers on pristine Au, and the electron injection barrier was reduced by 0.80eV for tris(8-hydroxyquinoline)aluminum (Alq3) and by 0.65eV for C60. The air-stable donor MV0 can thus be used to facilitate electron injection into organic semiconductors even from high work function metals.

1.
Z. V.
Vardeny
,
A. J.
Heeger
, and
A.
Dodabalapur
,
Synth. Met.
148
,
1
(
2005
).
2.
M. A.
Baldo
and
S. R.
Forrest
,
Phys. Rev. B
64
,
085201
(
2001
).
3.
C.
Di
,
G.
Yu
,
Y.
Liu
,
X.
Xu
,
Y.
Song
, and
D.
Zhu
,
Appl. Phys. Lett.
89
,
033502
(
2006
).
4.
S.
Veenstra
,
A.
Heeres
,
G.
Hadziioannou
,
G.
Sawatzky
, and
H.
Jonkman
,
Appl. Phys. A: Mater. Sci. Process.
75
,
661
(
2002
).
5.
W.
Osikowicz
,
X.
Crispin
,
C.
Tenstedt
,
L.
Lindell
,
T.
Kugler
, and
W. R.
Salaneck
,
Appl. Phys. Lett.
85
,
1616
(
2004
).
6.
S.
Duhm
,
A.
Gerlach
,
I.
Salzmann
,
B.
Bröker
,
R. L.
Johnson
,
F.
Schreiber
, and
N.
Koch
,
Org. Electron.
9
,
111
(
2008
).
7.
N.
Koch
,
S.
Duhm
,
J. P.
Rabe
,
A.
Vollmer
, and
R. L.
Johnson
,
Phys. Rev. Lett.
95
,
237601
(
2005
).
8.
Q. T.
Le
,
L.
Yan
,
Y.
Gao
,
M.
Mason
,
D. J.
Giesen
, and
C. W.
Tang
,
J. Appl. Phys.
87
,
375
(
2000
).
9.
M. Y.
Chan
,
S. L.
Lai
,
M. K.
Fung
,
S. W.
Tong
,
C. S.
Lee
, and
S. T.
Lee
,
Appl. Phys. Lett.
82
,
1784
(
2003
).
10.
Y.
Cao
,
G.
Yu
,
I. D.
Parker
, and
A. J.
Heeger
,
J. Appl. Phys.
88
,
3618
(
2000
).
11.
A.
Nakamura
,
T.
Tada
,
M.
Mizukami
, and
S.
Yagyu
,
Appl. Phys. Lett.
84
,
130
(
2003
).
12.
M.
Pfeiffer
,
K.
Leo
,
X.
Zhou
,
J. S.
Huang
,
M.
Hofmann
,
A.
Werner
, and
J.
Blochwitz-Nimoth
,
Org. Electron.
4
,
89
(
2003
).
13.
S.
Wang
,
K.
Kanai
,
E.
Kawabe
,
Y.
Ouchi
, and
K.
Seki
,
Chem. Phys. Lett.
423
,
170
(
2006
).
14.
C. K.
Chan
,
A.
Kahn
,
Q.
Zhang
,
S.
Barlow
, and
S. R.
Marder
,
J. Appl. Phys.
102
,
014906
(
2007
).
15.
G.
Parthasarathy
,
C.
Shen
,
A.
Kahn
, and
S.
Forrest
,
J. Appl. Phys.
89
,
4986
(
2001
).
16.
P.
Monk
, The Viologens: Physicochemical Properties, Synthesis and Applications of the Salts of 4, 4-bipyridine (
Wiley
,
New York
,
1999
).
17.
A.
Vollmer
,
O. D.
Jurchescu
,
I.
Arfaoui
,
I.
Salzmann
,
T. T. M.
Palstra
,
P.
Rudolf
,
J.
Niemax
,
J.
Pflaum
,
J. P.
Rabe
, and
N.
Koch
,
Eur. Phys. J. E
17
,
339
(
2005
).
18.
G.
Kresse
and
J.
Furthmüller
,
Comput. Mater. Sci.
6
,
15
(
1996
).
19.
G.
Kresse
and
J.
Hafner
,
Phys. Rev. B
47
,
558
(
1993
).
20.
G.
Heimel
,
L.
Romaner
,
J.-L.
Brédas
, and
E.
Zojer
,
Surf. Sci.
600
,
4548
(
2006
).
21.
H. J.
Monkhorst
and
J. D.
Pack
,
Phys. Rev. B
13
,
5188
(
1976
).
22.
M.
Methfessel
and
A. T.
Paxton
,
Phys. Rev. B
40
,
3616
(
1989
).
23.

Note that the sticking coefficient for MV0 may differ for Au(111) and the quartz microbalance surface; therefore, coverage values given for MV0 may not represent the actual molecular mass deposit.

24.
L.
Romaner
,
G.
Heimel
, and
E.
Zojer
,
Phys. Rev. B
77
,
045113
(
2008
).
25.
L.
Romaner
,
G.
Heimel
,
J.-L.
Brédas
,
A.
Gerlach
,
F.
Schreiber
,
R. L.
Johnson
,
J.
Zegenhagen
,
S.
Duhm
,
N.
Koch
, and
E.
Zojer
,
Phys. Rev. Lett.
99
,
256801
(
2007
).
26.
A.
Rajagopal
and
A.
Kahn
,
J. Appl. Phys.
84
,
355
(
1998
).
27.
H.
Suzuki
,
Appl. Phys. Lett.
69
,
1611
(
1996
).
28.
I. G.
Hill
,
A.
Kahn
,
Z. G.
Soos
, and
R. A.
Pascal
 Jr.
,
Chem. Phys. Lett.
327
,
181
(
2000
).
29.
H.
Ishii
,
K.
Sugiyama
,
E.
Ito
, and
K.
Seki
,
Adv. Mater. (Weinheim, Ger.)
11
,
605
(
1999
).
30.
A.
Kahn
,
N.
Koch
, and
W. Y.
Gao
,
J. Polym. Sci., Part B: Polym. Phys.
41
,
2529
(
2003
).
31.
P. S.
Bagus
,
V.
Staemmler
, and
C.
Wöll
,
Phys. Rev. Lett.
89
,
096104
(
2002
).
32.
R. W.
Lof
,
M. A.
van Veenendaal
,
B.
Koopmans
,
H. T.
Jonkman
, and
G. A.
Sawatzky
,
Phys. Rev. Lett.
68
,
3924
(
1992
).
33.
P. J.
Benning
,
D. M.
Poirier
,
T. R.
Ohno
,
Y.
Chen
,
M. B.
Jost
,
F.
Stepniak
,
G. H.
Kroll
,
J. H.
Weaver
,
J.
Fure
, and
R. E.
Smalley
,
Phys. Rev. B
45
,
6899
(
1992
).
34.
C.-T.
Tzeng
,
W.-S.
Lo
,
J.-Y.
Yuh
,
R.-Y.
Chu
, and
K.-D.
Tsuei
,
Phys. Rev. B
61
,
2263
(
2000
).
35.
A.
Crispin
,
X.
Crispin
,
M.
Fahlman
,
M.
Berggren
, and
W. R.
Salaneck
,
Appl. Phys. Lett.
89
,
213503
(
2006
).
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