Light-emitting polymer materials polymers

The electroluminescence of organic materials 2000 Progress in light-emitting polymers... 

There is no reason why the same principle cannot be applied for light-emitting polymers as host materials to pave a way to high-efficiency solution-processible LEDs. In fact, polymer-based electrophosphorescent LEDs (PPLEDs) based on polymer fluorescent hosts and lanthanide organic complexes have been reported only a year after the phosphorescent OLED was reported [8]. In spite of a relatively limited research activity in PPLEDs, as compared with phosphorescent OLEDs, it is hoped that 100% internal quantum efficiency can also be achieved for polymer LEDs. In this chapter, we will give a brief description of the photophysics beyond the operation of electrophosphorescent devices, followed by the examples of the materials, devices, and processes, experimentally studied in the field till the beginning of 2005. 

Light emitting diodes. 2. Polymers—Electric properties. 3. Electroluminescent devices—Materials. I. Li, Zhigang R., 1958- II. Meng, Hong, 1966- III. Optical science and engineering (Boca Raton, Fla.) 110. 

The use of conjugated light emitting polymers in the construction and commercialisation of organic LEDs is described in the section 3.8.6 on electroluminescence phenomena of Chapter 3. The rapid expansion of the development work on LEDs has inevitably led to the examination of luminescent conjugated polymers as materials for constructing laser diodes. 

Light emitting diodes - Materials. 2. Polymers - Surfaces. 3. Surface chemistry. 

These novel properties are the basis for a number of application including polymer light emitting diodes (LEDs), polymer light-emitting electrochemical cells (LECs), conducting polymers as electrochromic materials, polymer photodetectors and polymer photovoltaic cells. These application areas are discussed in detail in Section VII. 

Based on the presence of carbazole substituents, the blue-light emitting polymers (198) and (199) appear to be attractive materials for electroluminescence applications. Related polyphosphazenes (200) have been prepared aiming at photoreactive materials. " ... 

Altohyrtin C, which involved the synthesis of ylide (90) that contains the said side chain,and Xerulin, which inhibits the biosynthesis of cholesterol, which required the use of ylide (91). Wittig reactions are also useful reagents for the synthesis of polymeric materials, for example fluorene ylide (92) has been used to generate light emitting polymers. ... 

Light-emitting polymers are an important class of materials due to the promise which is brought by the aspects of applications (see references in Table 1). Early on, the marked fluorescence of PPEs in dilute solution was noted. Later on, it was shown that the fluorescence quantum yield of PPEs and PAEs in solutions can reach unity i.e., every absorbed photon is re-emitted (Table 12, entries 6—9). The rigid character of the PPEs seems to make intramolecular dissipation difficult, and insofar fluorescence is efficient. The attractive fluorescence behavior suggested that PAEs may find use in optoelectronic devices (vide infra). 

The indium tin oxide (ITO) anode layer is kept as thin as 15 mu to allow passage of the light emitted in the polymer. The cathode is fabricated from a material that has a small energy barrier with respect to electron emission, e.g., aluminum, calcium, or barium. 

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