Efficient blue electroluminescence, peaked at 436 nm, is demonstrated from polymer light-emitting diodes operating at high brightness. A dioctyl-substituted polyfluorene was used as the emissive layer in combination with a polymeric triphenyldiamine hole transport layer. The luminance reaches 600 cd/m2 at a current density of 150 mA/cm2 for a bias voltage of 20 V, corresponding to an efficiency of 0.25 cd/A and a luminosity of 0.04 lm/W. These values are optimized at a critical emissive layer thickness.

1.
J. H.
Burroughes
,
D. D. C.
Bradley
,
A. R.
Brown
,
R. N.
Marks
,
K.
Mackay
,
R. H.
Friend
,
P. L.
Burn
, and
A. B.
Holmes
,
Nature
347
,
539
(
1990
).
2.
D. D. C.
Bradley
,
Curr. Opin. Solid State Mater. Sci.
1
,
789
(
1996
).
3.
C.
Liedenbaum
,
Y.
Croonen
,
P.
van de Weijer
,
J.
Vleggaar
, and
H.
Schoo
,
Synth. Met.
91
,
109
(
1998
).
4.
G.
Grem
,
G.
Leditzky
,
B.
Ullrich
, and
G.
Leising
,
Adv. Mater.
4
,
36
(
1992
).
5.
S.
Tasch
,
A.
Niko
,
G.
Leising
, and
U.
Scherf
,
Appl. Phys. Lett.
68
,
1090
(
1996
).
6.
Y.
Yang
,
Q.
Pei
, and
A. J.
Heeger
,
J. Appl. Phys.
79
,
934
(
1996
).
7.
Y.
Ohmori
,
M.
Uchida
,
K.
Muro
, and
K.
Yoshino
,
Jpn. J. Appl. Phys., Part 2
30
,
L1941
(
1991
).
8.
Q.
Pei
and
Y.
Yang
,
J. Am. Chem. Soc.
118
,
7416
(
1996
).
9.
A. W.
Grice
,
A.
Tajbakhsh
,
P. L.
Burn
, and
D. D. C.
Bradley
,
Adv. Mater.
9
,
1174
(
1997
).
10.
P. L.
Burn
,
A. B.
Holmes
,
A.
Kraft
,
D. D. C.
Bradley
,
A. R.
Brown
, and
R. H.
Friend
,
J. Chem. Soc., Chem. Commun.
32
, (
1992
).
11.
C.
Hosowaka
,
N.
Kawasaki
,
S.
Sakamoto
, and
T.
Kusumoto
,
Appl. Phys. Lett.
61
,
2503
(
1992
).
12.
Q.
Pei
and
Y.
Yang
,
Adv. Mater.
7
,
559
(
1995
).
13.
I. D.
Parker
,
Q.
Pei
, and
M.
Marrocco
,
Appl. Phys. Lett.
65
,
1272
(
1994
).
14.
C.-C.
Wu
,
J. C.
Sturm
,
R. A.
Register
,
J.
Tian
,
E. P.
Dana
, and
M. E.
Thompson
,
IEEE Trans. Electron Devices
44
,
1269
(
1997
).
15.
N.
Miyaura
and
A.
Suzuki
,
Chem. Rev.
95
,
2457
(
1995
).
16.
M. Grell, D. D. C. Bradley, X. Long, T. Chamberlain, M. Inbasekaran, E. P. Woo, and M. Soliman, Acta Polym. (to be published).
17.
N. C.
Greenham
,
R. H.
Friend
, and
D. D. C.
Bradley
,
Adv. Mater.
6
,
491
(
1994
).
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