Soluble Segmented Stepladder poly(p-phenylenes) for Blue-Light-Emitting Diodes

Grem, G.; Paar, Christian; Stampfl, Jürgen; Leising, G.; Huber, Joachim; Scherf, Ullrich

doi:10.1021/cm00049a001

Cited by 67 publications

(42 citation statements)

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“…The "classical" synthesis to ladder polymers proceeds in two main steps: the chain formation via polymerization or polycondensation of suitable monomers followed by a polymer-analogous cyclization under generation of the double-stranded molecules [106,108] (Scheme 8).…”

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

“…By appropriate substitution (R 2 = -1,4-C 6 H 4 1C 10 H 21 in 42), soluble ladder-type polymers (LPPPs) are obtained with number-average molecular weights up to 25 000 (about 60 1,4-phenylene units) [108]. These PPP-type ladder structures are characterized by a two-component light emission: (i) a blue component can be assigned to the electroluminescence of single molecules and (ii) a yellow component corresponding to the emission of intermolecular aggregates [109].…”

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

“…Thus, by diluting ladder polymers in either a polystyrene or a polyvinylcarbazole polymer matrix, a strong suppression of the yellow luminescence is achieved [110]. A different strategy to suppress the formation of aggregates in order to produce blue-emitting devices is the use of new PPP-type step-ladder structures (43, Scheme 8b), whose distorted geometry prevents intramolecular aggregation [108,109]. The synthetic scheme for the statistical copolymer 43 is closely related to the generation of the homopolymer 42.…”

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

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The chemistry of electroluminescent organic materials

Segura¹

1998

Acta Polym.

287

200

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Electroluminescence has been a subject of interest for several decades because of its many applications in areas such as telecommunications or information displays. Light‐emitting diodes using p‐n junctions of inorganic semiconductors have dominated the field in the last twenty years; however, efficient blue emission has only recently been achieved and inorganic semiconductors are difficult to form over large areas, making the process uneconomic. During the last decade, an explosive growth of activity in the area of organic electroluminescence has occurred in both academia and industry, stimulated by the promise of light‐emitting plastics for the fabrication of large, flexible, inexpensive and efficient screens to be used in different applications. Thus, a substantial amount of research is presently directed towards color control and improvement of manufacturability and reliability of devices in order to make their commercialization viable. A great deal of work has been carried out by physicists and materials scientists concerned with the preparation of different device structures and with the use of different techniques for device manufacture. However, all this work would not be possible without the continuous efforts of synthetic chemists to prepare materials with enhanced luminescent properties and processabilities. This article provides a review of the main types of organic materials that have been used in the fabrica‐tion of light‐emitting diodes either as emitting materials or as charge‐transport layers. Special attention will be paid to the different synthetic strategies that have been followed in order to tune the color of the emission, to increase stability of materials and to enhance their processabilities.

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Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

See 1 more Smart Citation

The chemistry of electroluminescent organic materials

Segura¹

1998

Acta Polym.

287

200

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“…43,44 By comparing the integrated area of the PL spectra in Fig. 1(c), we obtain Q 0 ∼ = 50% at 5 K.…”

Section: 50mentioning

confidence: 86%

“…The PL quantum yields estimated at very low excitation power (P ) are ∼50% and ∼25% at 5 K and room temperature, respectively, which are consistent with previous reports. 43,44 The experimental setup of femtosecond time-resolved fluorescence upconversion spectroscopy has been used in our previous work, 45 which is similar to others in reports. [22][23][24][25][26][27][28][30][31][32] The laser source is a commercial τ p = 180 fs amplifier system (Coherent RegA 9000), which delivers 5.0-μJ pulses at 100 KHz and 780 nm (1.59 eV).…”

Section: Experimental Methodsmentioning

confidence: 99%

Femtosecond hot-exciton emission in a ladder-typeπ-conjugated rigid-polymer nanowire

Dai¹,

Monkman²

2013

Phys. Rev. B

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Publisher's copyright statement:Reprinted with permission from the American Physical Society: Phys. Rev. B 87, 045308 c (2013) by the American Physical Society. 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. A hot exciton is usually the initial elementary excitation product of the solid phase, particularly in lowdimensional photonic materials, which is a bottleneck to all subsequent processes. Measurement of hot-exciton emission (HExEm) is a great challenge due to fast E K relaxation and thus very weak transient emission. Here, we report the unambiguous observation of femtosecond HExEm from thin films of a model quasi-one-dimensional π -conjugated organic rigid-rod quantum nanowire, methyl-substituted ladder-type poly(para-phenylenes), using femtosecond time-resolved fluorescence spectroscopy. The results show clear HExEm from the cooling hot excitons, having a lifetime of ∼500 to ∼800 fs, and concomitant very weak density-dependent singlet-singlet annihilation (SSA) due to this ultrashort dwell time. The ultrafast dispersive migration of the relaxing excitons toward the bottom of the density of states occurs immediately after HExEm, which is simultaneous to the strong density-dependent SSA effect enhanced by the lengthening dwell time.

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Synthesis and characterization of a new green-emitting poly(phenylenevinylene) derivative containing alkylsilylphenyl pendant

Lee¹,

Yu²,

Kim³

et al. 2000

J. Polym. Sci. A Polym. Chem.

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A new type of processable green‐emissive polymer containing alkylsilylphenyl units was synthesized via Gilch polymerization. The resulting polymer was soluble in organic solvents and was spin‐cast to make a thin film. A light‐emitting diode was fabricated by the polymer being sandwiched between indium tin oxide and metal electrodes. A strong green emission at 524 nm was observed from the various device configurations made by the newly synthesized polymer. The polymer had a strong absorption band around 427 nm that was attributable to a π–π* transition of the conjugated segments of the polymer. A current–voltage–luminance curve showed typical rectifying diode characteristics. The polymer had a very high molecular weight (number‐average molecular weight = ∼300,000) with a polydispersity of about 3 and good thermal stability up to 400 °C. The brightness at 13 and 17 V was about 1000 and 5900 cd/m2, respectively. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4185–4193, 2000

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Soluble Segmented Stepladder poly(p-phenylenes) for Blue-Light-Emitting Diodes

Cited by 67 publications

References 0 publications

The chemistry of electroluminescent organic materials

The chemistry of electroluminescent organic materials

Femtosecond hot-exciton emission in a ladder-typeπ-conjugated rigid-polymer nanowire

Synthesis and characterization of a new green-emitting poly(phenylenevinylene) derivative containing alkylsilylphenyl pendant

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