electrophosphorescent performance of devices based on PVK
and Ir(ppy)3 was significantly enhanced by blending bipolar
spiro-fluorene material (FTzCz), due to facilitated charge injec-
tion and transport in the blends. Blend devices showed superior
performances relative to a neat PVK-based device. The
maximum luminance and maximum luminance efficiency were
50; (c) X. Gong, J. C. Ostrowski, G. C. Bazan, D. Moses and
A. J. Heeger, Appl. Phys. Lett., 2002, 81, 3711; (d) W. G. Zhu,
Y. Ke, F. Wang, C. Z. Liu, M. Yuan and Y. Cao, Synth. Met.,
2
003, 137, 1079.
10 (a) J. Kido, H. Shionoya and K. Nakai, Appl. Phys. Lett., 1995, 67,
2281; (b) X. Jiang, R. A. Register, K. A. Killeen, M. E. Thompson,
F. Pschenitzka, T. R. Hebner and J. C. Sturm, J. Appl. Phys., 2002,
9
1, 6717.
ꢀ2
ꢀ1
ꢀ2
4
940 cd m and 7.5 cd A at PVK : FTzCz ¼ 9 : 1, 4510 cd m
1
1 (a) C. Y. Jiang, W. Yang, J. B. Peng, S. Xiao and Y. Cao, Adv. Mater.,
2004, 16, 537; (b) X. H. Yang and D. Neher, Appl. Phys. Lett., 2004,
ꢀ1
and 9.9 cd A at PVK : FTzCz ¼ 8 : 2. Current results indicate
that the bipolar spiro-fluorene material FTzCz is a promising
additive for enhancing the performance of conventional PVK-
based electrophosphorescent devices.
8
4, 2476; (c) E. A. Plummer, A. V. Dijken, H. W. Hofstraat,
L. D. Cola and K. Brunner, Adv. Funct. Mater., 2005, 15, 281; (d)
X. H. Yang, F. Jaiser, S. Klinger and D. Neher, Appl. Phys. Lett.,
2
006, 88, 021107.
1
2 (a) M. E. Kondakova, T. D. Pawlik, R. H. Young, D. J. Giesen,
D. Y. Kondakov, C. T. Brown, J. C. Deaton, J. R. Lenhard and
K. P. Klubek, J. Appl. Phys., 2008, 104, 094501; (b) M. Mauro,
E. Q. Procopio, Y. H. Sun, C. H. Chien, D. Donghi, M. Panigati,
P. Mercandelli, P. Mussini, G. D’Alfonso and L. D. Cola, Adv.
Funct. Mater., 2009, 19, 2607; (c) F. C. Chen, S. C. Chien and
Y. S. Chen, Appl. Phys. Lett., 2009, 94, 043306.
Acknowledgements
We thank the National Science Council of the Republic of China
for financial aid through project NSC 98-2221-E-006-002-MY3.
1
3 (a) M. Kreyenschmidt, G. Klaerner, T. Fuhrer, J. Ashenhurst,
S. Karg, W. D. Chen, V. Y. Lee, J. C. Scoot and R. D. Miller,
Macromolecules, 1998, 31, 1099; (b) A. W. Grice, D. D. C. Bradley,
M. T. Bernius, M. Inbasekaran, W. W. Wu and E. P. Woo, Appl.
Phys. Lett., 1998, 73, 629.
Notes and references
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,
1990, 347, 539.
(a) G. Grem, G. Leditzky, B. Ullrich and G. Leising, Adv. Mater.,
14 (a) U. Scherf and E. J. W. List, Adv. Mater., 2002, 14, 477; (b)
S. Becker, C. Ego, A. C. Grimsdale, E. J. W. List, D. Marsitzky,
A. Pogantsch, S. Setayesh, G. Leising and K. M u€ llen, Synth. Met.,
2001, 125, 73.
2
1992, 4, 36; (b) Q. Pei and Y. Yang, J. Am. Chem. Soc., 1996, 118,
416; (c) M. R. Andersson, O. Thomas, W. Mammo, M. Svensson,
7
M. Theander and O. Ingan €a s, J. Mater. Chem., 1999, 9, 1933.
M. A. Baldo, D. F. O’Brien, M. E. Thompson and S. R. Forrest,
Phys. Rev. B: Condens. Matter Mater. Phys., 1999, 60, 14422.
(a) M. J. Yang and T. Tsutsui, Jpn. J. Appl. Phys., 2000, 39, L828; (b)
C. Adachi, M. A. Baldo, M. E. Thompson and S. R. Forrest, J. Appl.
Phys., 2001, 90, 5048.
(a) X. H. Yang and D. Neher, Appl. Phys. Lett., 2004, 84, 2476; (b)
S. A. Choulis, M. K. Mathai, V. E. Choong and F. So, Appl. Phys.
Lett., 2006, 88, 203502.
(a) S. M. King, H. A. Al-Attar, R. J. Evans, A. Congreve, A. Beeby
and A. P. Monkman, Adv. Funct. Mater., 2006, 16, 1043; (b)
C. L. Ho, W. Y. Wong, Z. Q. Gao, C. H. Chen, K. W. Cheah,
B. Yao, Z. Y. Xie, Q. Wang, D. G. Ma, L. X. Wang, X. M. Yu,
H. S. Kwok and Z. Y. Lin, Adv. Funct. Mater., 2008, 18, 319.
(a) M. Gross, D. C. Nuller, H. G. Nothofer, U. Scherf, D. Neher,
C. Brauchle and K. Meerholz, Nature, 2000, 405, 661; (b)
D. F. O’Brien, C. Giebeler, R. B. Fletcher, A. J. Cadby,
L. C. Palilis, D. G. Lidzey, P. A. Lane, D. D. C. Bradley and
W. Blau, Synth. Met., 2001, 116, 379; (c) P. A. Lane, L. C. Palilis,
D. F. O’Brien, C. Giebeler, A. J. Cadby, D. G. Lidzey,
A. J. Campbell, W. Blau and D. D. C. Bradley, Phys. Rev. B:
Condens. Matter, 2001, 63, 235206.
(a) X. Gong, J. C. Ostrowski, D. Moses, G. C. Bazan and
A. J. Heeger, Adv. Mater., 2002, 14, 581; (b) F. C. Chen, Y. Yang,
M. E. Thompson and J. Kido, Appl. Phys. Lett., 2002, 80, 2308.
(a) X. Chen, J. L. Liao, Y. Liang, M. O. Ahmed, H. E. Tseng and
S. C. Chen, J. Am. Chem. Soc., 2003, 125, 636; (b) W. Zhu, C. Liu,
L. Su, W. Yang, M. Yuan and Y. Cao, J. Mater. Chem., 2003, 13,
15 (a) A. Babel and S. A. Jenekhe, Macromolecules, 2003, 36, 7759; (b)
N. S. Cho, D.-H. Hwang, B.-J. Jung, E. Lim, J. Lee and
H.-K. Shim, Macromolecules, 2004, 37, 5265; (c) C.-S. Wu,
Y.-J. Yang, S.-W. Fang and Y. Chen, J. Polym. Sci., Part A:
Polym. Chem., 2012, 50, 3875; (d) C.-S. Wu, Y.-T. Lee and
Y. Chen, Polym. Chem., 2012, 3, 2776; (e) C.-S. Wu, C.-T. Liu and
Y. Chen, Polym. Chem., 2012, DOI: 10.1039/c2py20506h.
16 (a) D. M. Pai, J. F. Yanus and M. Stolka, J. Phys. Chem., 1984, 88,
4714; (b) H. Kanai, S. Ichinosawa and Y. Sato, Synth. Met., 1997,
91, 195; (c) M. Ikai, S. Tokito, Y. Sakamoto, T. Suzuki and
Y. Taga, Appl. Phys. Lett., 2001, 79, 156.
17 (a) M. Strukelj, F. Papadimitrakopoulos, T. M. Miller and
L. J. Rothberg, Science, 1995, 267, 1969; (b) A. W. Grice,
A. Tajbakhsh, P. L. Burn and D. D. C. Bradley, Adv. Mater., 1997,
9, 1174.
18 (a) C. Adachi, M. A. Baldo, S. R. Forrest and M. E. Thompson,
Appl. Phys. Lett., 2000, 77, 904; (b) S.-H. Chen and Y. Chen,
Macromolecules, 2005, 38, 53; (c) T. Yasuda, T. Imase,
Y. Nakamura and T. Yamamoto, Macromolecules, 2005, 38,
4687.
3
4
5
6
7
19 (a) C.-S. Wu and Y. Chen, Macromolecules, 2009, 42, 3729; (b)
C.-S. Wu and Y. Chen, J. Mater. Chem., 2010, 20, 7700; (c)
C.-S. Wu and Y. Chen, J. Polym. Sci., Part A: Polym. Chem., 2010,
48, 5727; (d) C.-S. Wu, S.-L. Lee and Y. Chen, J. Polym. Sci., Part
A: Polym. Chem., 2011, 49, 3099; (e) C.-S. Wu and Y. Chen,
J. Polym. Sci., Part A: Polym. Chem., 2011, 49, 3928.
8
9
20 D. R. Coulson, L. C. Satek and S. O. Grim, Inorg. Synth., 1972,
13, 121.
2
3884 | J. Mater. Chem., 2012, 22, 23877–23884
This journal is ª The Royal Society of Chemistry 2012