Fluorescence and Phosphorescence in Organic Materials

Köhler, Anna; Wilson, Joanne S.; Friend, Richard H.

doi:10.1002/1527-2648(20020717)4:7<453::aid-adem453>3.0.co;2-g

Cited by 42 publications

(23 citation statements)

References 68 publications

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“…The carrier pairs recombine into either singlet or triplet molecular excitons. In pure hydrocarbon compounds, luminescence is dominated by fluorescence from the singlet, with most triplet excitons undergoing non-radiative decay 29 . In contrast, in organometallic complexes with strong singlet-triplet intersystem crossing in the excited state, radiative recombination from the higher-lying singlet is suppressed so that phosphorescence dominates [30][31] .…”

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“…In contrast, in organometallic complexes with strong singlet-triplet intersystem crossing in the excited state, radiative recombination from the higher-lying singlet is suppressed so that phosphorescence dominates [30][31] . Few materials actually show dual singlet-triplet luminescence, and mostly this can only be identified under time-resolved detection at low temperatures [29][30][31][32] . Very few reports of dual luminescence exist for OLEDs [33][34][35][36][37] .…”

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Visualizing the radical-pair mechanism of molecular magnetic field effects by magnetic resonance induced electrofluorescence to electrophosphorescence interconversion

et al. 2017

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Visualizing the radical-pair mechanism of molecular magnetic field effects by magnetic resonance induced electrofluorescence to electrophosphorescence interconversion

et al. 2017

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“…3 These high efficiencies originate from the strong spin orbit coupling present in these heavy metal complexes which makes it possible for both singlet and triplet excitons generated to decay radiatively. 4,5 A large number of iridium complexes have been utilized for this purpose, which are mostly based on the cyclometalating ligand 2-phenylpyridine (ppy) with an auxiliary ligand such as acetylacetonate (acac) or picolinate (pic). [6][7][8][9][10] Several groups have demonstrated tuning of the phosphorescence wavelength from blue to red by functionalization of the ligands with electron withdrawing and electron donating substituents.…”

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Highly phosphorescent perfect green emitting iridium(iii) complex for application in OLEDs

et al. 2007

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A novel iridium complex, [bis-(2-phenylpyridine)(2-carboxy-4-dimethylaminopyridine)iridium(III)] (N984), was synthesized and characterized using spectroscopic and electrochemical methods; a solution processable OLED device incorporating the N984 complex displays electroluminescence spectra with a narrow bandwidth of 70 nm at half of its intensity, with colour coordinates of x = 0.322; y = 0.529 that are very close to those suggested by the PAL standard for a green emitter.Organic light emitting diodes (OLEDs) are becoming increasingly successful as a new display technology. 1,2 Although OLED displays have reached commercialization, there is still a need for improvement of the efficiency, colour purity and stability. This is true for multilayered OLEDs prepared via vacuum evaporation and even more so for OLED architectures obtained via solution processing. The latter technique offers a more economic production route and hence is of great interest for the more widespread application of the OLED technology. The introduction of iridium(III) containing complexes led to very efficient multilayered OLEDs, reaching internal conversion efficiency of almost 100%. 3 These high efficiencies originate from the strong spin orbit coupling present in these heavy metal complexes which makes it possible for both singlet and triplet excitons generated to decay radiatively. 4,5 A large number of iridium complexes have been utilized for this purpose, which are mostly based on the cyclometalating ligand 2-phenylpyridine (ppy) with an auxiliary ligand such as acetylacetonate (acac) or picolinate (pic). [6][7][8][9][10] Several groups have demonstrated tuning of the phosphorescence wavelength from blue to red by functionalization of the ligands with electron withdrawing and electron donating substituents. [11][12][13] Nevertheless, no attempts were made to tune the colour purity by decreasing the emission bandwidth, which of course is attractive for both fundamental research and practical applications. Therefore, in this communication we report a novel approach for tuning bandwidth by modulating the LUMO levels of the ancillary ligand.The N984 complex was synthesized in one step by reacting the dimeric iridium(III) complex [Ir(ppy) 2 (Cl)] 2 with methyl-dimethylamino-picolinate and sodium carbonate in 2-ethoxy-ethanol affording the N984 compound as a yellow powder.{ The 1 H NMR spectrum of the N984 complex shows 19 resonance signals (two doublets (d), five doublet of doublets (dd), six doublet of doublet of doublets (ddd) and six doublet of triplets (dt); see Fig. S1) in the aromatic region. The pyridine 6-H protons of the 2-phenylpyridine ligands are assigned to ddd at d 7.64 and d 8.82 on the basis of the distinctive pattern of the coupling constants expected for these substituted pyridines (J 3,6 0.8, J 4,6 1.6 and J 5,6 5.8). The different magnetic environments of these protons are a result of the trans geometry of the pyridine rings which directs one 6-H proton towards the 4-dimethylaminopyridine ring and the other towards the car...

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“…Among all phosphorescent emitters under investigation, iridium (III) complexes are without contest among the most widely studied transition metal complexes: as neutral emitters [24] or as soft salts [25][26][27] for the design of OLEDs or as ionic complexes [28][29][30] for the design of Light-Emitting Electrochemical Cells (LECs). As main advantage over the other transition metal complexes, relatively short excited state lifetime enables to e ciently minimize the triplet-triplet (T-T) annihilation [31,32]. So far, metal complexes that are nearly non-emissive at room temperature but revealing a decent emission at 77K have only been scarcely in-vestigated as emitters for OLEDs [33].…”

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White and Saturated Blue Phosphorescent OLED based on the Non-Emissive Homoleptic Complex Ir(ppz)3 as single active material

Lepeltier

Dumur

Wantz

et al. 2014

Optical Data Processing and Storage

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Fluorescence and Phosphorescence in Organic Materials

Cited by 42 publications

References 68 publications

Visualizing the radical-pair mechanism of molecular magnetic field effects by magnetic resonance induced electrofluorescence to electrophosphorescence interconversion

Visualizing the radical-pair mechanism of molecular magnetic field effects by magnetic resonance induced electrofluorescence to electrophosphorescence interconversion

Highly phosphorescent perfect green emitting iridium(iii) complex for application in OLEDs

White and Saturated Blue Phosphorescent OLED based on the Non-Emissive Homoleptic Complex Ir(ppz)3 as single active material

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