Light emitting poly(para-phenylenevinylene-alt-3-tert butyl-meta-phenylenevinylenes)
| Autor: | Eric Styche, Liming Ding, Ananda M. Sarker, Frank E. Karasz, E. Elif Gürel, Paul M. Lahti |
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| Rok vydání: | 2003 |
| Předmět: |
chemistry.chemical_classification
Olefin fiber Photoluminescence Materials science Mechanical Engineering Metals and Alloys Polymer Electroluminescence Condensed Matter Physics Photochemistry Electronic Optical and Magnetic Materials chemistry Mechanics of Materials Excited state Wittig reaction Materials Chemistry Luminescence Cis–trans isomerism |
| Zdroj: | Synthetic Metals. 132:227-234 |
| ISSN: | 0379-6779 |
| Popis: | Poly(para-phenylenevinylene-alt-3-tert-butyl-meta-phenylenevinylene) was synthesized by Wittig condensation with varying ratio of cis and trans olefin bonds. The luminescent properties of the unisomerized and trans-isomerized polymers (1 and 2, respectively) were compared. Nearly identical emission spectra were observed for both polymers in dilute solutions, but the emission intensity of 1 is lower. This is attributed to the cis vinylic moieties in 1, which favor nonradiative excited state decay processes by limiting formation of a planar excited state. Double layer LEDs with the configuration ITO/PPV/(1 or 2)/Ca–Al were fabricated. Substantially better efficiencies and luminances were observed for devices made with polymer 2 as the emissive layer, by comparison to 1. The results show that the elimination of cis olefin defects in these polymers is important for the optimization of LEDs. |
| Databáze: | OpenAIRE |
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