Organometallic compounds comprising an imidazole carbene ligand having a N-containing ring fused to the imidazole ring are provided. In particular, the N-containing ring fused to the imidazole ring may contain one nitrogen atom or more than one nitrogen atom. These compounds may demonstrate high photoluminescent (PL) efficiency, Gaussian emission spectra, and/or short excited state lifetimes. These materials may be especially useful as blue phosphorescent emitters.

Conjugates comprising a drug, cell or biological molecule bound to a photoluminescent polymer nanoparticle, in particular a cross-linked polyfluorene nanoparticle, are described herein, as well as their methods of manufacture and their uses in biological imaging and sensing applications.

Provided is an organic EL device having high efficiency and high driving stability while being driven at a low voltage. The organic electroluminescent device includes one or more light-emitting layers between an anode and a cathode opposite to each other. At least one of the light-emitting layers contains a host material and a light-emitting dopant, and (i) a first host formed of an indolocarbazole compound having one or two indolocarbazole rings, and (ii) a second host formed of a carbazole compound having a plurality of carbazole rings and having a bond structure represented by the following general formula (3) are used as the host material.

Novel compounds comprising heteroleptic iridium complexes are provided. The compounds have a particular combination of ligands which includes a single pyridyl dibenzo-substituted ligand. The compounds may be used in organic light emitting devices, particularly as emitting dopants, to provide devices having improved efficiency, lifetime, and manufacturing.

An organic compound is disclosed comprising: a first chemical moiety with a structure of formula I, ##STR00001##
and two second chemical moieties, each with a structure of formula II, ##STR00002##
wherein the first chemical moiety is linked to each of the two second chemical moieties via a single bond.

A compound represented by the following general formula is excellent in light emission properties. R.sup.1 and R.sup.2 each independently represent a fluorinated alkyl group, D represents a substituent in which Hammett's σ.sub.p value is negative, and A represents a substituent in which Hammett's σ.sub.p value is positive. ##STR00001##

The present disclosure relates in part to compounds capable of emitting delayed fluorescence and uses of these compounds in organic light-emitting diodes.

An embodiment of the present disclosure provides an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first delayed fluorescent dopant and a first phosphorescent dopant and disposed between the first and second electrodes, wherein a percentage by weight of the first phosphorescent dopant with respect to the first delayed fluorescent dopant is equal to or less than 5.

Provided is a light emitting device including a lower electrode, an upper electrode disposed to face the lower electrode, a quantum dot light emitting layer between the lower electrode and the upper electrode, an electron transport layer between the lower electrode and the quantum dot light emitting layer, and a hole transport layer between the upper electrode and the quantum dot light emitting layer, wherein the quantum dot light emitting layer includes a quantum dot, and a first ligand on a surface of the quantum dot, and a second ligand on the surface of the quantum dot.

An organic light emitting device including: a substrate; a first electrode; a second electrode; and an organic layer interposed between the first electrode and the second electrode and including an emission layer, wherein one of the first electrode and the second electrode is a reflective electrode and the other is a semitransparent or transparent electrode, and wherein the organic layer includes a layer having at least one of the compounds having at least one carbazole group, and a flat panel display device including the organic light emitting device. The organic light emitting device has low driving voltage, excellent current density, high brightness, excellent color purity, high efficiency, and long lifetime.