Highest OLEDs

Blue fluorescent emitters based on fused polyaromatic ring systems have long been known and systematic work has steadily improved the efficiencies and colors, while pushing the limits of stability in an operational device. A sky blue based on styrylamine doped 2-methyl-9,10-di(2-naphthyl)anthracene OLED was reported to provide the highest efficiency device (Scheme 3.99) [365],... 

In the vapor-deposited OLED community, a number of approaches have been employed to produce white light emission. White OLEDs have been demonstrated based on multilayer structures, e.g., stacked backlights [153,168], multidoping of single-layer structures [145], phosphorescent monomer-excimer emission layers [169] and on doping of phosphorescent materials into separate bands within the emission zone, called a tri-junction [170]. The trijunction device has produced the highest white OLED efficiency of 16% external quantum efficiency demonstrated thus far [171]. 

Fig. 1.20. Schematic energy band diagram of a two-layer organic light emitting diode (OLED), in which tin-doped indium oxide (ITO) is used to inject holes into the highest occupied molecular orbital (HOMO) and a low work function metal to inject electrons into the lowest unoccupied molecular orbital (LUMO)...

Hydride-based precatalysts (R = H) showed the highest initiation rates in a-ole-fin polymerization (Table 1, see p. 980) and this efficiency was later often assigned to the in situ formation of terminal Ln-H moieties. For 4(Sc) it was shown that the order of decreasing rate of ethylene insertion is Sc-H > Sc-CH2(CH2) CH3 (n > 2) > SC-CH2CH2CH3 > Sc-CHj > SC-CH2CH3 >... 

The highest efficiency OLED utilizing a spiro-terfluorene (compound 51) in a double confinement device structure [185], reaches an external quantum efficiency (EQE) of 5.3%, or 1.53 cd A-1, with CIE coordinates of (0.158, 0.041). Others using similar double confinement structures have achieved... 

In addition, chiral oligofluorenes have exhibited circularly polarized electroluminescence with the highest polarization to date, as characterized by the dissymmetry factor, without addition of optical elements external to the OLED device. This device had an efficiency of 0.94 cd A-1 in the deep blue,... 

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