Light-emitting polymers , classes

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). 

Here we recall a few important physical concepts and technological issues related to the properties of stimulated emission and lasing action shown by a few classes of light-emitting polymer nanofibers. These fibers are better presented in Seetion 5.5. A complete, definitive description of the operation principles of laser materials can be found in the book by O. Svelto. Furthermore, for readers interested in more details on organic lasers, excellent specialized reviews exist in the literature. ... 

As a class of n-type organic semiconductors, PBI derivatives have received considerable attention for a variety of applications [312, 313], for example, for organic or polymer light-emitting diodes (OLEDs and PLEDs) [314, 315], thin-film organic field-effect transistors (OFETs) [316, 317], solar cells [318, 319], and liquid crystals [320]. They are also interesting candidates for single-molecule device applications, such as sensors [321], molecular wires [322], or transistors [141]. 

Phenylene-based polymers are one of the most important classes of conjugated polymers, and have been the subject of extensive research, in particular as the active materials in light-emitting diodes (LEDs) [1,2] and polymer lasers [3]. These materials have been of particular interest as potential blue emitters in such devices [4], The discovery of stable blue-light emitting materials is a major goal of research into luminescent polymers [5]. Poly(para-phenylene) (PPP, Scheme 1, 1) is a blue emitter [6], but it is insoluble and so films of PPP have to be prepared via precursor routes [7]. Substitution with long alkyl... 

Abstract Poly(dibenzosilole)s are an emerging class of polymers with similar optoelectronic properties to polyfluorenes. With increased stability towards oxidation, several poly(dibenzosilole)-based devices, such as light emitting diodes, have shown improved performance over their polyfluorene counterparts. As a consequence of reduced conjugation in the polymer chain, some poly(dibenzosilole)s have high triplet excited state energies, which make them suitable hosts for blue triplet emitters in electrophosphores-cent devices. 

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