Polyfluorene derivatives

M. Fukuda, K. Sawada, and K. Yoshino, Synthesis of fusible and soluble conducting polyfluorene derivatives and their characteristics, J. Polym. Set, Part A Polym. Chem., 31 2465-2471, 1993. 

G. Klaerner and R.D. Miller, Polyfluorene derivatives effective conjugation lengths from well-defined oligomers, Macromolecules, 31 2007-2009, 1998. 

J. Pei, X.-L. Liu, Z.-K. Chen, X.-H. Zhang, Y.-H. Lai, and W. Huang, First hydrogen-bonding-induced self-assembled aggregates of a polyfluorene derivatives, Macromolecules, 36 323-327, 2003. 

W.-L. Yu, J. Pei, W. Huang, and A.J. Heeger, Spiro-functionalized polyfluorene derivatives as blue light-emitting materials, Adv. Mater., 12 828-831, 2000. 

Q. Peng, M. Xie, Y. Huang, Z. Lu, and D. Xiao, New series of highly phenyl-substituted polyfluorene derivatives for polymer light-emitting diodes, J. Polym. ScL, Part A Polym. Chem., 42 2985-2993, 2004. 

I. Levesque, A. Donat-Bouillud, Y. Tao, M. D lorio, S. Beaupre, P. Blondin, M. Ranger, J. Bouchard, and M. Leclerc, Organic tunable diodes from polyfluorene derivatives, Synth. Met., 122 79-81, 2001. 

P. Blondin, J. Bouchard, S. Beupre, M. Belletete, G. Duroche, and M. Leclerc, Molecular design and characterization of chromic polyfluorene derivatives, Macromolecules, 33 5874-5879, 2000. 

Q. Peng, Z.-Y. Lu, Y. Huang, M.-G. Xie, S.-H. Han, J.-B. Peng, and Y. Cao, Synthesis and characterization of new red-emitting polyfluorene derivatives containing electron-deficient 2-pyran-4-ylidene-malononitrile moieties, Macromolecules, 37 260-266, 2004. 

HOMO energy level of the polymer is 5.32 eV. It was demonstrated that the EL performance of super yellow PPV and blue polyfluorene derivatives using this hole transport polymer is comparable to or better than that using PEDOT PSS as a HTL [102],... 

AS Dhoot and NC Greenham, Triplet formation in polyfluorene derivatives, Adv. Mater., 24 1834-1837, 2002. 

G. Lieser, M. Oda, T. Miteva, A. Meisel, H.-G. Nothofer, U. Scherf, D. Neher, Ordering, Graphoepitaxial Orientation and Conformation of a Polyfluorene Derivative of the Hairy-rod Type on an Oriented Substrate of Polyimide, Macromokcules 2000, 33, 4490-4495. 

High-performance polyfluorene derivatives consisting of 9,9-bis(4-hydroxyphenyl)-fluorene and 4,4 -bis((4-chlorophenyl)sulfonyl)-l,l -biphenyl have been prepared using reagent ratios from 100 0 to 0 100. When poly(9,9-bis(4-hydroxyphenyl)-fluorene) was prepared it had a M of 58,000 daltons with a glass transistion temperature greater then 300°C. When copolymers of 9,9-bis(4-hydroxyphenyl)-fluorene and 4,4-hydroxybiphenyl were prepared, however, the glass transition temperature was lowered by up to 30°C. 

In Fig. 4 the after-pulse growth of the PR-TRMC transients due to positive ion scavenging by different Tt-bond conjugated polymers in oxygen saturated benzene is illustrated. From kinetic fits to the transients, using the known free-ion yield in benzene, the intrachain hole mobility could be determined and the values were found to vary from a low of 0.02 cm /Vs for the polythiophene to a high of 0.74 cm /Vs for the polyfluorene derivative. Mobility values in the... 

Scheme 1 Polyfluorene derivatives with Ir(III) complex on the side-chain...

Our group [44,45] first synthesized a series of polyfluorene derivatives (polymer 28-30) with charged red-light emitting Ir(III) complexes in the backbones, in which the phosphorescent chromophores were molecularly dispersed within the composite material. Saturated red-light emission can be... 

Scheme 10 Chemical structure of polyfluorene derivatives with on-chain Pt(II) complexes showing molecular wire behavior...

Fluorene oligomers have seen only limited use in organic solar cells to date. If they incorporate any fluorene units at all, most efforts have focused on polyfluorene derivatives [19,20]. For example, Bryce et al. synthesized a series of oligofluorene-fullerene derivatives to study their fundamental photophysical and charge transfer properties [216] (compounds 62-67 in Fig. 17), but have not pursued such structures for organic solar cells yet. 

Fig. 4 Chemical structure of PDMOF and geometry of a polyfluorene derivative chain. Reprinted with permission from [28]. (2004) by the American Chemical Society...

A major deviation from the above picture was found by Ramsdale et al., who investigated bilayer solar cells based on two polyfluorene derivatives [125]. When compared to the work function of both electrodes, the authors measured a Voc exceeding those values by about 1 eV. This overpotential has been accounted for by a concentration driven diffusion current. 

In combination with a C70 fullerene derivative—PTPF70—the system yielded improved power conversion efficiencies of 0.7% due the increased absorption of the C70 derivative [208,210]. Using similar polyfluorene derivatives, power conversion efficiencies of about 0.9% (APFO-Green2) [212[ and 2.2% (APFO-Green5) [213] were achieved. Other low band gap polymers, with absorption spectra extending up to 1100 run, yielded efficiencies of aroimd 1% [214-217]. 

Persson N-K, Schubert M, Inganas O (2004) Optical modelling of a layered photovoltaic device with a polyfluorene derivative/fullerene as the active layer. Sol Energy Mater Sol Cells 83 169... 

Lee SK, Cho NS, Kwak JH, Lim KS, Shim H-K, Hwang D-H, Brabec CJ (2006) New low band-gap alternating polyfluorene derivatives for photovoltaic cells. Thin Solid Films 511-512 157... 

The polymers used in this chapter are all polyfluorene derivatives. They are ABAB copolymers with A being the fluorene group shown in Fig. 2.4(a). Due to their high chemical stability, flexible chemistry and good charge transport and luminescence properties, polyfluorenes are very common materials for polymer optoelectronics and have been used to make highly efficient LEDs [26, 13] as well as good photovoltaic diodes [27, 28] and transistors [29]. Table 2.1 lists the abbreviated and full names of all the polymers that appear in this chapter. The chemical structures of each of the polymers are displayed in Fig. 2.4. 

In the long time limit Eq. (3.27) can be approximated by yrrA tL04 [114-]. This has been verified experimentally in a polyfluorene derivative [163], In this study the DF as well as the triplet concentration was monitored as a function of time and temperature to investigate the influence of dispersion on triplet-triplet annihilation. Since the attainment of dynamic equilibrium of triplet relaxation is temperature and time dependent it can by monitored via time resolved detection of DF. According to theory [164] and MC simulation [165] the time ts where the dispersive to nondispersive transition of relaxation occurs, is given by ... 

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