Green phosphorescent dopants

FIGURE 7.10 Luminous efficiency (open squares) and power efficiency (filled circles) versus luminance for a PHOLED incorporating an improved green phosphorescent dopant. 

SCHEME 3.1 Chemical structures of anthracene, a hole transport triarylamine, an electron transport and a green emitter Alq3, and a phosphorescent dopant PtOEP. 

Once again, the most recent developments have been in the area of green phosphorescent materials where phenomenal efficiencies are now beginning to be coupled with good device lifetimes. The prototypical emitter of this type is iridium-tris-2-phenylpyridine (Ir(ppy)3) used as a dopant (Scheme 3.98), usually diluted into a carbazole type host, because it is prone to serious self-quenching problems. 

Nakayama et al. reported highly efficient and stable single-stack white phosphorescent OLEDs based on blue triplet emitter KMBD-342 described in Section 14.4.2.3. Yellow-green (YD-85) and red (RD-61) dopants used in the device were provided by Universal Display Corporation. The device layer structure was as follows Light outcoupling film ITO HIL HTL green EML red EML I blue EML HBL n-doped ETL A1. At 1000cd/m the performance... 

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