Optoelectronic Properties and Nanostructure Formation of σ-Conjugated Polymers

Seki, Shu; Tagawa, S.

doi:10.1295/polymj.pj2006222

Cited by 40 publications

(17 citation statements)

References 82 publications

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“…[39] The films of 1S 3 ·CA showed reproducible transient conductivity (fSm) with maximum value of 1.4 10 À5 cm 2 V À1 s À1 upon excitation with incident laser pulses at 355 nm and subsequent decays are observed (Figure 5 b). The observed TRMC signals indicate the generation of mobile charge carriers upon photoexcitation followed by their extinction through trapping and/or recombination events.…”

Section: Hierarchical Organization Of Hydrogen-bonded Complexmentioning

confidence: 94%

Rational Construction of Perylene Bisimide Columnar Superstructures with a Biased Helical Sense

Seki

Asano

Seki

et al. 2011

Chemistry A European J

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Discotic supramolecular complexes bearing six perylene bisimide (PBI) chromophores were prepared by mixing monotopically triple-hydrogen-bonding melamines equipped with two PBI chromophores and two 3,7-dimethyloctyl chiral handles with tritopically triple-hydrogen-bonding cyanuric acid (CA). UV/Vis and fluorescence titration experiments demonstrated that the discotic complexes were formed in methylcyclohexane by the 3:1 complexation between the melamines and CA. TEM and AFM studies revealed that the complexes hierarchically organize into fibrous columnar assemblies, which eventually results in the formation of organogels. Circular dichroism (CD) and flash-photolysis time resolved microwave conductivity measurements revealed the presence of extended chiral stacks of PBI chromophores within the columns. The anisotropy factors of the columnar assemblies are remarkably high (g=1.5×10(-3)) when considering the presence of only one 3,7-dimethyloctyl chiral handle per perylene chromophore, suggesting that the columnar structures have a biased helical sense. The fact that the chiral centers are located inside the discotic complexes rather than at their peripheries might be unique structural property responsible for the rather strong optical activities for the assemblies of this chromophore. The effective transcription of the molecular chirality to the extended columnar assemblies through the formation of unique discotic complexes enables the expression of "majority-rules" chiral amplification effect, which is unprecedented for the supramolecular assemblies of PBIs.

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Section: Hierarchical Organization Of Hydrogen-bonded Complexmentioning

confidence: 94%

Rational Construction of Perylene Bisimide Columnar Superstructures with a Biased Helical Sense

Seki

Asano

Seki

et al. 2011

Chemistry A European J

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“…The electron effective mass are calculated on the upper valence band ( m H ) or lower conduction band ( m L ), which is a good parameter for predicting the hole or electron mobility 39. As shown in Table 2, the relatively smaller band gap and effective mass of the PTHTP compared to the other three copolymers could facilitate the π‐electron delocalization and have potential applications for thin film transistors, transparent conductor, and photovoltaic devices 10‐12, 40, 41…”

Section: Resultsmentioning

confidence: 99%

Small band gap conjugated polymers based on thiophene–thienopyrazine copolymers

Cheng

Liu

Chen

2007

J. Polym. Sci. A Polym. Chem.

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In this study, five small band gap thiophene (TH)–thienopyrazine (TP) conjugated copolymers were synthesized by Stille‐coupling reaction. The polymer structures consisted of one to four thiophene rings with the TP of different side groups provided a systematical investigation on the structure–electronic property relationship. The absorption maxima of the polymer films decreased from 850 to 590 nm as the thiophene moieties increased from thiophene to quaterthiophene. The optical and electrochemical band gaps of the studied poly[2,3‐didodecyl‐5‐(thiophen‐2‐yl)thieno[3,4‐b]pyrazine] (PTHTP‐C12) were 0.97 and 0.78 eV, respectively, indicating a significant intramolecular charge transfer. The theoretical geometry and electronic properties of the TH‐TP copolymers by the density functional theory at the B3LYP level and 6‐31G(d) basis set suggested that the bond length alternation enlarged with enhancing the thiophene content and resulted in the variation on the polymer band gap. The relatively small theoretical effective mass of poly(TH‐alt‐TP) also indicated its potential applications for field transistor applications. Our study demonstrates the tunable electronic properties of small band gap copolymers by the thiophene content and the resulted geometry variation. Such polymers could be potentially used for near‐infrared electronic and optoelectronic devices. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5872–5883, 2007

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“…Polysilanes are -conjugated polymers with strong -electron delocalization along the main chain. Hence they are a promising candidate for charge transport applications [10][11][12]. Polysilanes, in general, have a direct-gap semiconductor.…”

Section: Introductionmentioning

confidence: 99%