Iridium triplet emitters

Keywords Dye-sensitized solar cells Iridium triplet emitters ... 

Clearly, using a triplet emitter with shorter excited state lifetime should improve the device efficiency. In 2002, Cao and coworkers [65] used iridium complexes Ir(ppy)3 (3) and its... 

C Lee, KB Lee, and J Kim, Polymer phosphorescent light-emitting devices doped with tris (2-phenylpyridine) iridium as a triplet emitter, Appl. Phys. Lett., 77 2280-2282, 2000. 

Iridium Complexes as Triplet Emitters in Organic Light-Emitting Diodes 149... 

Keywords Emission quantum yields High-resolution spectroscopy Iridium complexes OLED emitters Organometallic compounds Phosphorescence Photophysics Platinum complexes Radiative rates Spin-orbit coupling Triplet emitters Zero-field splitting SOC ZFS SOC and geometry SOC paths... 

The active layer of three of these devices contained orange-emitting iridium(III) triplet emitter and green-emitting Au-CdSe/ZnS nanocrystals in the molar ratios... 

Polysilanes are also applicable as matrix materials in phosphorescent OLEDs. Mixtures of polysilanes and triplet emitters are sufficient to effect an energy transfer from polysilane triplet states to emitter triplet states, thus amplifying the luminescence of the device. It has been shown that if polysilanes have electrophosphorescent side chains consisting of triplet emitters, the energy transfer from polysilane to emitter is most effective [124]. Thus the beneficial electronic properties of polysilanes are perfectly combined with the spectroscopic properties of transition metal based triplet emitters. The compounds described are derivatives of polymethylphenylsi-lanes, (Fig. 24) which are covalently attached to triplet emitters with iridium as metal centre. The polymers were applied in OLEDs with an ITO/active layer/Ca/Ag layer sequence. The active layer contained a fraction of 70% by weight of the... 

Fig. 24 Polysilanes with covalently attached iridium based triplet emitters. Polymers (a) and (b) give green phosphorescent OLEDs while polymer (c) emits blue light...

The development of phosphorescent iridium organometallic complexes was another major breakthrough [8]. Such iridium complexes are triplet emitters and enhance the theoretical quantum efficiency of OLEDs from 25% for fluorescent... 

Another efficient material introduced by the same group is the green emitting /ac-tris(2-phenylpyridine)iridium [Ir(ppy)3, 67] [38], A suitable host for this phosphorescent emitter is CBP (10). The triplet lifetime is rather short, the experimentally determined value being 500 ns in the CBP matrix. Another iridium complex was shown to emit in the red with high efficiency due to the short phosphorescence lifetime in comparison with PtOEP [165]. 

Rothe C, King S, Monkman AP (2006) Systematic study of the dynamics of triplet ex-citon transfer between conjugated host polymers and phosphorescent iridium (III) guest emitters. Phys Rev B 73 245208... 

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