Disclosed are an organic compound based on triazine and benzoxazole and an application thereof in an OLED device. The compound of the present application has a relatively high glass transition temperature and molecular thermal stability, is low in absorption and high in refractive index in the field of visible light, and is capable of effectively improving the light extraction efficiency of an OLED device when applied to a capping layer of the OLED device; with a deep HOMO energy level and high electronic mobility, the compound of the present application can be used as the hole blocking layer or the electron transport layer material, so that the recombination degree of the hole and the electron in the light-emitting layer can be improved, and thus the light-emitting efficiency of the OLED device can be enhanced and the service life of the OLED device can be prolonged.

The purpose of the present invention is to provide: a π-conjugated compound exhibiting excellent light emission characteristics; an organic electroluminescent element using same; a display device; and an illumination device. Accordingly, this organic electroluminescent element is provided with: a positive electrode; a negative electrode; and at least one organic layer which is sandwiched between the positive electrode and the negative electrode, and which includes a light emission layer. The light emission layer includes a π-conjugated compound having a structure represented by any of general formulae (1)-(3) ##STR00001##
(in general formulae (1)-(3), at least one among R1-R4, R5-R8, and R9-R16 represents a group represented by general formula (4) ##STR00002##
(in general formula (4): Ar1 and Ar2 represent substituted or unsubstituted aryl groups; L1 represents a single bond or a substituted or unsubstituted arylene group; and # represents a bond to general formulae (1)-(3))).

Provided are a condensed cyclic compound represented by Formula 1 and an organic light-emitting device including the same: ##STR00001##
wherein, in Formula 1, X.sub.1, A.sub.1, L.sub.11, a11, Ar.sub.11, Ar.sub.12, b11, R.sub.11, R.sub.12, c11, and c12 are the same as defined in the specification.

The present disclosure relates to a plurality of host materials comprising a first host material including a compound represented by formula 1 and a second host material including a compound represented by formula 2, and an organic electroluminescent device comprising the same. In addition, the present disclosure relates to an organic electroluminescent compound, and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound and/or a specific combination of compounds according to the present disclosure as host materials, an organic electroluminescent device having high luminous efficiency and long lifespan property can be provided.

An organic compound and a manufacturing method thereof, and an organic light emitting diode electroluminescent device are provided. The organic compound has a suitable HOMO energy level and a high hole mobility. Compared with traditional hole transport materials, when the organic compound is applied in a hole transport layer of the organic light emitting diode electroluminescent device, the organic light emitting diode electroluminescent device has enhanced maximum current efficiency, maximum external quantum efficiency, and service lifespans.

An organic-EL-display device includes a blue-emitting-organic-EL-device and a red-emitting-organic-EL-device as pixels, in which each of the blue-emitting-organic and the red-emitting-organic-EL-device includes a light-reflection layer, transparent electrode, hole transporting zone, emitting layer, electron transporting zone and semitransmissive electrode in this order, the blue-emitting-organic-EL-device has a blue-emitting layer containing a fluorescent-compound FLB, the red-emitting-organic-EL-device has a red-emitting layer containing a delayed fluorescent compound DFR, the hole transporting zone is provided at a constant film-thickness in a shared manner across the blue-emitting and red-emitting organic EL devices, the red-emitting-organic-EL-device has a resonator structure whose order of interference is first-order between the light reflection layer and the semitransmissive electrode, a film-thickness of the red-emitting layer is less than 50 nm, and a sum of film-thicknesses of the transparent electrode and hole transporting zone in the blue-emitting and red-emitting organic EL devices is less than 40 nm.

Provided are an electroluminescent compound having a structure represented by Formula I, a thermally activated delayed fluorescence material and an application thereof. The electroluminescent compound has TADF characteristics and may be applied to a light emitting layer of an OLED device as a thermally activated delayed fluorescence material. The OLED device includes an anode, a cathode, and at least one organic thin film layer comprising the thermally activated delayed fluorescence material in a light emitting layer between the anode and the cathode. The electroluminescent compound effectively reduces the overlap between HOMO and LUMO through special molecular structure design, so that ΔE.sub.ST is reduced to less than 0.25 eV, which satisfies reverse crossing of energy from a triplet state to a singlet state, effectively improves transmission capacities of two kinds of carriers, improves carrier balance, and thus significantly improves light emitting efficiency of the OLED device.

In one aspect, π-conjugated asymmetric molecular dyes are described herein comprising a donor (D)-acceptor (A) architecture across a thiazolothiazole electronic bridge. In some embodiments, a π-conjugated asymmetric molecular dye has a difference between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of at least 1.2 eV. In some embodiments, the HOMO-LUMO offset is 1.2 eV to 5 eV. The π-conjugated asymmetric molecular dye may also display a change in dipole moment between ground and excited states of at least 5 D.

The present specification relates to a compound represented by Chemical Formula 1, a composition for forming an optical film and an optical film comprising the same, and a display device comprising the optical film.

The device provided herein is an organic electroluminescent device and includes a substrate; a first electrode on the substrate and with high reflectivity; a translucent or transparent second electrode over the first electrode; and a first, a second and a third organic layer included between the first and the second electrode; where the second organic layer has a thickness >80 nm and is made of a second organic material; the third organic layer is a light-emitting layer including at least one light-emitting material and at least one host material; the first organic layer has a conductivity >1×10.sup.−4 S/m and <1×10.sup.−2 S/m; an energy level difference between HOMO energy level of the second organic material and HOMO energy level of the at least one host material is <0.27 eV; and the first electrode and the second organic layer are in direct contact with the first organic layer.