A light emitting material containing an adjustment compound N in addition to a donor compound D and an acceptor compound A that form an exciplex and satisfying HOMO(D)>HOMO(N)>HOMO(A), LUMO(D)>LUMO(N)+0.1 eV and LUMO(N)>LUMO(A) has improved luminous efficiency or emission lifetime.

A light-emitting device including: m emitting units located between a first electrode and a second electrode; and m−1 charge generation units, each located between two neighboring emitting units among the m emitting units and including an n-type charge generation layer and a p-type charge generation layer. The m emitting units may each include an emission layer, at least one of the m emission layers comprises a first emission layer and a second emission layer that are in contact with each other, the first emission layer includes a first host, a second host, and a first dopant, the second emission layer includes a third host, a fourth host, and a second dopant, the first host and the second host form a first exciplex, the third host and the fourth host form a second exciplex, and the first dopant is a delayed fluorescence dopant, and the second dopant is a phosphorescent dopant.

A light-emitting device includes a light-emitting layer. The light-emitting layer includes a host material. The host material includes a p-type material and an n-type material. The p-type material and the n-type material are configured to form an exciplex. An absolute value of a difference between a wavelength corresponding to a peak of a normalized fluorescence emission spectrum of the exciplex and a wavelength corresponding to a peak of a normalized fluorescence emission spectrum of the n-type material being less than or equal to 5 nm.

An organic electroluminescent device, a display panel and a display apparatus. The organic electroluminescent device comprises: an anode and a cathode, which are arranged opposite each other; an organic electroluminescent layer, which is located between the anode and the cathode; a hole blocking layer, which is located between the organic electroluminescent layer and the cathode; and an electron transport layer, which is located between the hole blocking layer and the cathode, wherein the organic electroluminescent layer comprises: an exciplex formed by means of mixing an electron-type light-emitting host material and a hole-type light-emitting host material, and a light-emitting guest material doped in the exciplex; and the electron mobility of the electron transport layer is greater than that of the hole blocking layer, and the electron mobility of the hole blocking layer is greater than that of the electron-type light-emitting host material.

Provided are substituted acetylacetonate compounds. Also provided are formulations comprising these substituted acetylacetonate compounds. Further provided are OLEDs and related consumer products that utilize these substituted acetylacetonate organometallic compounds.

A multicolor light-emitting element using fluorescence and phosphorescence, which has a small number of manufacturing steps owing to a relatively small number of layers to be formed and is advantageous for practical application can be provided. In addition, a multicolor light-emitting element using fluorescence and phosphorescence, which has favorable emission efficiency is provided. A light-emitting element which includes a light-emitting layer having a stacked-layer structure of a first light-emitting layer exhibiting light emission from a first exciplex and a second light-emitting layer exhibiting phosphorescence is provided.

Cyclometallated iridium complexes having triphenylene or aza triphenylene and bulky alkyl substitution that can be used as emitters in OLEDs to improve the external quantum efficiency (EQE) and lifetime of OLEDs are disclosed.

Cyclometalated iridium complexes having triphenylene or aza triphenylene and bulky alkyl substitution that can be used as emitters in OLEDs to improve the external quantum efficiency (EQE) and lifetime of OLEDs are disclosed.

The present invention relates to an organic electroluminescent device including at least one light-emitting layer B composed of one or more sublayers, wherein the one or more sublayers of the light-emitting layer B include at least one host material H.sup.B, at least one phosphorescence material P.sup.B, at least one small FWHM emitter S.sup.B, and optionally at least one TADF material E.sup.B, wherein S.sup.B emits light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV.

Provided is a light-emitting device including an organometallic compound represented by Formula 1-1 or 1-2, an electronic apparatus including the light-emitting device, and the organometallic compound represented by Formula 1-1 or 1-2, wherein Formulae 1-1 and 1-2 are respectively the same as those described in the present specification.

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