Synthesis and characterization of new fluorene-acceptor alternating and random copolymers for light-emitting applications

Wu, Wen Chung; Liu, Cheng‐Liang; Chen, Wen‐Chang

doi:10.1016/j.polymer.2005.11.058

Cited by 176 publications

(91 citation statements)

References 42 publications

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“…The solution photoluminescence spectra also show a similar trend. Both polymers have a high emission maxima than those of PF with (424 and 445 nm) reported previously, 13 due to the lower band gap of the former. Figure 4 shows the cyclic voltammograms of PF-p-In and PF-m-In and the corresponding electrochemical results are listed in Table I d The HOMO energy levels were calculated from cyclic voltammetry and were referenced to ferrocene (4.8 eV).…”

Section: Electronic and Optoelectronic Propertiesmentioning

confidence: 53%

“…The glass transition temperatures (T g ) of PF-p-In and PF-m-In are 109 and 156 C, respectively. Note that the T d and T g of the polyfluorene (PF) homopolymer are 409 and 67 C. 13 The higher thermal stability of the PF-p-In and PF-m-In than that of PF is due to the incorporation of ladder-like indolocarbazole backbone into polymer structure. The higher T g of the PF-m-In than that of PF-p-In could be due to the less rotational freedom of the former because of the steric hindrance on the meta-position structure.…”

Section: Resultsmentioning

confidence: 99%

“…The incorporation of acceptor and donor-acceptor-donor moiety into polyfluorene also successfully improved the EL or FET characteristics. [12][13][14][15] Indolocarbazole-based materials have emerged as new p-type organic semiconductors due to relatively high hole-transporting mobility and photo-oxidative stability. Relatively high hole mobilities of 0.2 and 0.02 cm 2 V À1 s À1 were reported for the indolo[3,2-b]carbazole [18][19][20] and polymer derivatives, [21][22][23] respectively.…”

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confidence: 99%

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Synthesis of New Fluorene-Indolocarbazole Alternating Copolymers for Light-Emitting Diodes and Field Effect Transistors

Lee

Chen

Chueh

et al. 2008

Polym J

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New alternating copolymers of poly (2,7-(9,9 0 -dihexylfluorene)-alt-3,9-(5,11-di(2-ethylhexyl)-indolo[3,2-b]carbazole)) (PFp-In) and poly (2,7-(9,9 0 -dihexylfluorene)-alt-2,8-(5,11-di(2-ethylhexyl)-indolo[3,2-b]carbazole)) (PF-m-In) were synthesized by palladium-catalyzed Suzuki coupling polymerization and characterized for the applications of light-emitting diodes and field effect transistors (FET). The incorporation of indolocarbazole into polyfluorene could not only enhance hole transporting properties but also thermal properties. The para-linkage, PF-p-In, facilitates -electron delocalization and thus has a lower optical band gap and a higher emission maximum than those of the meta linkage, PF-m-In. The electroluminescence devices based on PF-p-In and PF-m-In as the emissive layer show a similar maximum luminance but with different emissive colors of green and blue, respectively. The FET hole mobilities of PF-p-In and PF-m-In are 6:73 Â 10 À5 and 1:50 Â 10 À4 cm 2 /VÁs, respectively, which are significantly higher than that of polyfluorene. The present study demonstrates the electronic and optoelectronic properties of polyfluorene enhanced by incorporating hole transporting indolocarbazole with different linkages.KEY WORDS: Functional Polymers / Polymer Synthesis / Light-Emitting Diodes / Field Effect Transistors / Fluorene / Indolocarbazole / Conjugated polymers have been extensively studied for various electronic and optoelectronic devices, such as electroluminescence displays, photovoltaic cells, and field effect transistors.1-5 Oligo-and polyfluorene as well as their derivatives are excellent candidates for optoelectronic applications because they exhibit high thermal/chemical stability, excellent fluorescence quantum yields, and solution processibility.6,7 However, the relatively high ionization potential and low electron affinity of poly(9,9-dialkylfluorene) lead to poor carrier injection from the electrodes. Thus, limited electroluminescence (EL) efficiency and insignificant or no field effect mobility were reported in the literature. 8,9The electronic and optoelectronic properties of polyfluorene could be improved through the approaches of copolymer, blend, side chain modification, end-capping, or nanofiber and result in enhanced device characteristics. [8][9][10][11][12][13][14][15][16][17] For example, the copolymers of fluorene with hole transporting moieties of phenothiazine and phenoxazine led to enhanced EL characteristics 8 and field effect mobility, 9 respectively. The incorporation of acceptor and donor-acceptor-donor moiety into polyfluorene also successfully improved the EL or FET characteristics.12-15 Indolocarbazole-based materials have emerged as new p-type organic semiconductors due to relatively high hole-transporting mobility and photo-oxidative stability. Relatively high hole mobilities of 0.2 and 0.02 cm 2 V À1 s À1 were reported for the indolo[3,2-b]carbazole [18][19][20] and polymer derivatives, 21-23 respectively. Hence, it would be of interest to explore the synthesis and...

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Section: Electronic and Optoelectronic Propertiesmentioning

confidence: 53%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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Synthesis of New Fluorene-Indolocarbazole Alternating Copolymers for Light-Emitting Diodes and Field Effect Transistors

Lee

Chen

Chueh

et al. 2008

Polym J

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“…Among them are donor-acceptor pairs mediated by salt bridges [13], thienopyrazine-based copolymers [14], n-type conjugated polymers based on electron-deficient tetraazabenzodifluoranthene diimide [15][16][17][18], etc. Such conjugated polymer semiconductors with electron donor-acceptor transfer have become of growing interest for organic electronic applications [19][20][21][22], such as photovoltaic cells [23][24][25], light emitting diodes (LEDs) [26][27][28][29], and field-effect transistors [30][31][32][33]. During the past decade more evidence for the electron transport in DNA [34][35][36][37][38] (see review [39]) has also been reported.…”

Section: Introductionmentioning

confidence: 99%

Donor-acceptor electron transport mediated by solitons

2014

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Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modied, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We study the long-range electron and energy transfer mediated by solitons in a quasi-one-dimensional molecular chain (conjugated polymer, alpha-helical macromolecule, etc.) weakly bound to a donor and an acceptor. We show that for certain sets of parameter values in such systems an electron, initially located at the donor molecule, can tunnel to the molecular chain, where it becomes self-trapped in a soliton state, and propagates to the opposite end of the chain practically without energy dissipation. Upon reaching the end, the electron can either bounce back and move in the opposite direction or, for suitable parameter values of the system, tunnel to the acceptor. We estimate the energy efficiency of the donor-acceptor electron transport depending on the parameter values. Our calculations show that the soliton mechanism works for the parameter values of polypeptide macromolecules and conjugated polymers. We also investigate the donor-acceptor electron transport in thermalized molecular chains.

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“…de Suzuki e de Yamamoto [37][38][39]. Nessas reações arilas bifuncionalizadas são unidas por meio de ligações simples, na presença de um metal de transição.…”

Section: Polifluorenosunclassified

Fotoquímica de polímeros conjugados contendo centros de transferência de carga e migração de energia

Simas¹

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A Deus pela oportunidade de reforma pessoal através do trabalho edificante. Pelo amparo constante nos momentos de incerteza, medo e desânimo.Ao Prof. Dr. Marcelo Henrique Gehlen pela oportunidade, orientação e, sobretudo, pelas valiosas lições de trabalho.À CAPES pela bolsa concedida e à FAPESP e CNPq pelo suporte financeiro.Ao IQSC pelo apoio institucional.À Profª Drª Leni Akcelrud e ao Arnaldo Glogauer por terem cedido os polímeros PFOPPV e PFPPV.Ao Prof. Dr. Roberto G. S. Berlinck e à aluna Simone P. de Lira pelas análises de LC-MS dos compostos M2 e BNI.Ao Prof. Dr. Benedito S. Lima Neto pela grande assistência na síntese, e análises de GPC, dos polímeros PF-BNI e PF. E em especial, aos alunos José Luiz S. Sá e Gustavo Metzker, pela imensa boa vontade com que prontamente se dispuseram a me ajudar com os procedimentos em atmosfera inerte, requeridos na síntese dos polímeros.Ao Prof. Dr. Lino Misoguti e ao aluno Jonathas P. Siqueira pelas medidas de transiente de absorção dos polímeros PF-BNI e PF.À Profª Drª Melissa F. S. Pinto, pelos cálculos químico-quânticos dos compostos BNI e FBNI.Aos técnicos do CAQI, Mauro Fernandes, Paulo Cordeiro e Sylvana Agustinho pelo auxílio com as técnicas espectroscópicas e cromatográficas.Ao grupo de Fotoquímica pelo auxílio constante nos percalços e necessidades diárias. À Bernadete Figueiredo, pelo esforço para conseguir os artigos e livros pedidos por mim em tempos de greve.Aos amigos do Laboratório de Fluorescência Molecular, Ana, Carol, Denís, Rafael e Robson pela grande ajuda, torcida e descontração, durante todo esse tempo.À Maria Silva Zoccoli pelo imenso apoio e ajuda sincera ao longo de quase dez anos.Aos queridos amigos Ângela, Arnaldo, Carolina, Juliano, Raphaela, Thaís e Vitor, pelo carinho, apoio e camaradagem de sempre.À minha família amada, representação sublime dos valores mais elevados da vida, pelo afeto sincero e incondicional, que justifica e dá sentido a tudo na vida. Whereas the PFPPV backbone is fully conjugated, the chromophore segment in PFOPPV backbone is confined between aliphatic (-(CH 2 ) 8 -) flexible segments. The excited-state dynamics of both copolymers is characterized by the presence of conjugated moieties containing cis and trans isomers. The segmented structure of PFOPPV allows the resonant energy transfer between the chromophores, which is provided by dipole-dipole interactions. The energy transfer process leads to the depolarization of PFOPPV fluorescence emission. For PFPPV the energy migration occurs in less than 20 ps and the fluorescence decay is ascribed to the emission of chromophore segments containing cis and trans, already in a photostationary condition. Dessa forma, a viabilidade de aplicação dos polímeros conjugados em eletrônica molecular, requer o conhecimento da dinâmica e dos mecanismos de relaxação de estado excitado desses materiais. Torna-se então necessária a determinação de parâmetros importantes, tais como escala de tempo e distância, envolvidos nos processos de transferência de energia de excitação eletrônica em p...

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Synthesis and characterization of new fluorene-acceptor alternating and random copolymers for light-emitting applications

Cited by 176 publications

References 42 publications

Synthesis of New Fluorene-Indolocarbazole Alternating Copolymers for Light-Emitting Diodes and Field Effect Transistors

Synthesis of New Fluorene-Indolocarbazole Alternating Copolymers for Light-Emitting Diodes and Field Effect Transistors

Donor-acceptor electron transport mediated by solitons

Fotoquímica de polímeros conjugados contendo centros de transferência de carga e migração de energia

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