DOI: 10.1039/C3CC46151C
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ChemComm
of FF with solvent polarity and a positive slope with good linear
Notes and references
fit in Lippert-Mataga plot strongly confirm the presence of ICT in
a
Address, Polymer Division, Council of Scientific and Industrial
Research(CSIR)- CLRI, Adyar, Chennai – 600 020, CSIR-Network of
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FF in accordance with previous report. There was no change in
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the PL measurement in the concentration range of 10 to 10 M 55 Institutes for Solar Energy, India. Fax: +91-044-24911589; Tel: +91-
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(Figure 8S, 9S)† which confirmed the absence of eximer
formation in solution of FF.
044-24437189; E-mail: nsomanathan@rediffmail.com,
somanathan@clri.res.in.
b
Address, Chemical Laboratory, Council of Scientific and Industrial
Though ICT is responsible for emission as observed in FF and
FM, a low transition dipole moment associated with FF is
responsible for high emission. In the case of FM, larger transition
dipole moment and associated vibronic relaxation, rendered it
non emissive in solution and thin film. In FF, J-Aggregate
formation as induced by planarization in aggregates and thin film
Research(CSIR)- CLRI, Adyar, Chennai – 600 020, CSIR-Network of
Institutes for Solar Energy, India.
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c
Address, Photosciences and photonics, CSIR – National Institute for
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Interdisciplinary Science and Technology (NIIST), Council of Scientific
and Industrial Research(CSIR), Thiruvananthapuram – 695 019, India.
† Electronic Supplementary Information (ESI) available: [NMR,
MALDI-Mass, Experimental details, computational details and specific
discussions are presented in ESI]. See DOI: 10.1039/b000000x/
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(
evident from red shift in emission) lead to AIEE, in contrast to
the other AIE systems containing tetraphenylethylene wherein a
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typical blue shift is observed upon aggregation. However, in
this study, the addition of cyano group resulted in virtually
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J. dong Luo, Z. Xie, J. W. Y. Lam, L. Cheng, H. Chen, C. Qiu, H. S.
Kwok, X. Zhan, Y. Liu, D. Zhu, B. Z. Tang, Chem. Commun., 2001,
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complete quenching of FM in contrast to previous studies.
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Figure 4. (a) PL and EL spectra of FF; (b) Current voltage (I-V) and
luminescence voltage (L-V) traces of OLED with FF as emissive layer.
80
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0
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C. -C. Chang, M. -C. Hsieh, J. -C. Linand, T. -C. Chang,
Biomaterials, 2012, 33, 897.
J. Liu, Q. Meng, X. Zhang, X. Lu, P. He, L. Jiang, H. Dong, W. Hu,
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Light emitting diodes from FF with device configuration of
ITO/PEDOT:PSS/FF/Al were fabricated by solution processing.†
The electroluminescence (EL) spectrum of LED matched very
closely with the PL spectrum in thin film (Figure 4). The LED
showed a bright yellow emission with Commission Internationale
de l´Eclairage (CIE) coordinates of (0.46, 0.52) with low turn on
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0
C. Chi, C. Im, V. Enkelmann, A. Ziegler, G. Lieser, G. Wegner,
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voltage of 3.5 V The maximum brightness was observed to be
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6551 cd/m at 14 V. The luminous efficiency (η
) and power
C,max
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efficiency (ηP,max) were found to be 12.3 cdA and 7.8 lmW ,
respectively. These values indicate that the optimization of device
fabrication can improve the performance of LED. The brightness
is more than that of most of the related systems reported in earlier
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10 W. Z. Yuan, Y. Gong, S. Chen, X. Y. Shen, J. W. Y. Lam, P. Lu, Y.
Lu, Z. Wang, R. Hu, N. Xie, H. S. Kwok, Y. Zhang, J. Z. Sun and B.
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studies.
The L-V and I-V traces are presented in Figure 4.The
charge carrier mobility of FF obtained by space charge limited
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current (SCLC) method was found to be 1.28 x 10 .
100 11 S. V. Bhosale, C. H. Jani, C. H. Lalander, S. J. Langford, I. Nerush, J.
In summary, a novel solution processable luminogen with
AIEE and good film formation property has been reported. To the
best of our knowledge, the fluorophore, FF is the first example of
an AIEE solution processable luminogen with fluorenone as
G. Sharper, D. Villamaina, E. Vauthey, Chem. Commun., 2011, 47,
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05 13 L. Deng, W. Wu, H. Guo, J. Zhao, S. Ji, X. Zhang, X. Yuan, C.
Zhang, J. Org. Chem., 2011, 76, 9294.
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central stator. LED fabricated with FF showed a brightness of
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6551 cd/m at 14 V, one of the highest, reported for single layer
LED with AIE/AIEE luminogen. This work may open new
avenues and directions in designing new luminogens with AIEE.
Further studies in the designing of new AIEE luminogens and
white light emitting systems are in progress.
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M. Sauer, J. Hofkens, J. Enderlein, Handbook of Fluorescence
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The Authors thank Council of Scientific and Industrial Reserch
(
CSIR), India for financial support through NWP 55. The author,
S. J. Ananthakrishnan specially thanks CSIR, India for Senior
Research Fellowship (Grant Number. 31/6(0340)/2010-EMR-I).
We thank Prof Dr. R. Dhamodharan, Mr. E. Ramachandran, IIT
madras for their help.
J. Am. Chem. Soc., 2004, 126, 10232.
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