Red electrophosphorescence of novel Ir-complexes in PLEDs

Greenish‐yellow‐, yellow‐, and orange‐light‐emitting iridium(III) polypyridyl complexes with poly(ε‐caprolactone)–bipyridine macroligands

“…Despite this fact, iridium(III) complexes are highly appealing because of their wide range of emission energies, long lifetimes, and high quantum yields 10–12. The study of emissive and redox‐active d 6 ‐transition‐metal complexes, such as those of iridium(III) and ruthenium(II), has been extended in recent years to applications in light‐emitting devices and in light‐emitting electrochemical cells 13–27. For potential applications in such devices or in display technology, it is of importance to have phosphorescent emitters that are easily processed, do not aggregate or decay, and have high quantum yields and lifetimes of several microseconds.…”

Mixed iridium(III) and ruthenium(II) polypyridyl complexes containing poly(ε‐caprolactone)‐bipyridine macroligands

“…In particular, the design of luminescent and redox‐active transition‐metal complexes and the study of their photochemical, photophysical, and electrochemical properties has been intensively studied in the last years because of their potential application to light‐emitting devices4–18 and solar cells 19–21. To prevent formation of aggregates, which often leads to self‐quenching and to reduced device lifetimes, incorporation of metal complexes into the polymers is helpful.…”

New preparative procedure for photoluminescent metallopolymers having a biphenyl‐2,2′‐diyl iridium(III) unit bound to a phosphine copolymer ligand

“…Although iridium(III) complexes containing C,N ‐chirated iridacycles1–5 have been employed as most of the low‐molecular‐weight dopants that emit efficiently, iridium(III) phosphine complex 1a has a C,C ‐chirated 2,2′‐biphenylene ligand 17. As shown in Figure 1, which depicts the excitation and emission spectra for complex 1a in the solid state, compound 1a emitted red luminescence at 618 nm in the solid state when irradiated from at least 250 to 600 nm, although the luminescence could not be observed in a chloroform solution 19.…”

“…In comparison with emitting devices made of OLEDs, easy construction and low driving voltages in devices containing PLEDs are the predominant factors because PLED devices require a smaller number of layers. Two types of PLED materials are well known: (1) polymers in which luminescent small molecules are doped into polymer hosts such as poly(vinyl carbazole) and poly(9,9‐di‐ n ‐octyl‐2,7‐fluorene)1–6 and (2) polymers having luminescent units in their main chain or side chain. In the former polymers, phase separation and crystallization of the small molecules in the polymer matrix may reduce the luminescence efficiency and prevent uniform emissions all over the films.…”