The present disclosure relates to organometallic compounds and formulations and their various uses including as hosts or emitters in devices such as organic light emitting diodes and related electronic devices. In particular, the present disclosure provides are compounds having the structure of Formula I as defined herein. Also provided are formulations comprising these compounds. Further provided are OLEDs and related consumer products that utilize these compounds.

A light-emitting element includes a light-emitting layer including a guest, an n-type host and a p-type host between a pair of electrodes, where the difference between the energy difference between a triplet excited state and a ground state of the n-type host (or p-type host) and the energy difference between a triplet excited state and a ground state of the guest is 0.15 eV or more. Alternatively, in such a light-emitting element, the LUMO level of the n-type host is higher than the LUMO level of the guest by 0.1 eV or more, or the HOMO level of the p-type host is lower than the HOMO level of the guest by 0.1 eV or more.

A light-emitting element including a fluorescent material as a light-emitting material and having high emission efficiency is provided. The light-emitting element includes a pair of electrodes and an EL layer provided between the pair of electrodes. The EL layer includes a host material and a guest material. The host material is capable of exhibiting thermally activated delayed fluorescence at room temperature. The guest material is capable of exhibiting fluorescence. The second triplet excitation energy level of the guest material is higher than or equal to the lowest singlet excitation energy level of the guest material.

A condensed cyclic compound represented by Formula 1: ##STR00001## wherein in Formula 1, Ar.sub.1 and R.sub.1 to R.sub.8 are the same as described in the specification.

An organic light-emitting device including a first electrode, a second electrode facing the first electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer, wherein the emission layer includes a host and a dopant, and wherein the organic light-emitting device satisfies predetermined conditions described in the specification.

The present invention relates to an organic light emitting device comprising a light emitting layer and an electron transport layer which satisfy the following mathematical expressions, E.sub.HOMO-ET>E.sub.HOMO-BH and E.sub.LUMO-ET>E.sub.LUMO-GH, and having improved driving voltage, efficiency, and lifetime.

The present invention relates to organic electroluminescent devices comprising a light-emitting layer B comprising a host material H.sup.B, a first thermally activated delayed fluorescence (TADF) material E.sup.B, and a depopulation agent S.sup.B.

The present invention includes a novel series of host materials for OLEDs based on substituted fused 1,2,4-triazines, represented by Formula I. The invention also includes an organic light-emitting device comprising an anode, a cathode, and an organic layer, disposed between the anode and the cathode, comprising a compound of Formula I. The compounds of the invention may improve the device EQE and lifetime. ##STR00001##

A condensed cyclic compound represented by Formula 1 and an organic light-emitting device including the same: ##STR00001##
wherein, in Formulae 1, Y.sub.11 is a group represented by Formulae 2-1 to 2-3 and Y.sub.12 is a group represented by Formulae 3-1 to 3-5, 4-1, or 4-2 as described herein.

A self-luminous element includes: a pixel electrode; a light-emitting layer that is disposed above the pixel electrode and includes a light-emitting material; a first functional layer that is disposed on the light-emitting layer and includes a metal fluoride; a second functional layer that is disposed on the first functional layer and includes a first organic material having at least one of electron transport properties and electron injection properties; and a counter electrode that is disposed above the second functional layer. The second functional layer does not include at least one metallic element selected from the group consisting of alkali metals, alkaline earth metals, and rare earth metals that reduce the metal fluoride.