The disclosure relates to organic electroluminescent elements, compounds for use in the elements, and devices using the elements, which include a compound represented by the following General Formula (1): ##STR00001##
where R.sup.1 to R.sup.3 and R.sup.6 to R.sup.8 each independently represents a hydrogen atom, which may be a deuterium atom, or a substituent with a Hammett substituent constant σ.sub.p value of −0.15 or more, R.sup.5, R.sup.9 and R.sup.10 each independently represents a hydrogen atom or a substituent, L.sup.1 represents a divalent linking group, DG.sup.1 represents a donor group, and n1 represents 1 or 2, and where R.sup.1 to R.sup.3, R.sup.5 to R.sup.10, L.sup.1, and DG.sup.1 are not bound to each other to form a ring.

Provided is a light-emitting element with high emission efficiency including a fluorescent material as a light-emitting substance. In a light-emitting element including a pair of electrodes and an EL layer between the pair of electrodes, a delayed fluorescence component due to triplet-triplet annihilation accounts for 20% or more of light emitted from the EL layer, and the light has at least one emission spectrum peak in the blue wavelength range. The EL layer includes an organic compound in which an energy difference between the lowest singlet excited energy level and the lowest triplet excited energy level is 0.5 eV or more. The EL layer includes a benzo[a]anthracene compound.

A spirobifluorene compound and a perovskite solar cell including the spirobifluorene compound are disclosed. More particularly, a spirobifluorene compound which can be used as a hole transport material of a perovskite solar cell is disclosed. A perovskite solar cell including the spirobifluorene compound as a hole transport material is further disclosed.

Provided are a heterocyclic compound and an organic light-emitting device including the same. The heterocyclic compound includes a fluoro-containing cyclic group. The heterocyclic compound does not include a carbazole group, a dibenzofuran group, a dibenzothiophene group, and/or a triphenylene group. The organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an organic layer, the organic layer including an emission layer and at least one of the heterocyclic compound.

The present specification relates to a heterocyclic compound represented by Chemical Formula 1, and an organic light emitting device comprising the same.

Provided is a light-emitting element with high emission efficiency including a fluorescent material as a light-emitting substance. In a light-emitting element including a pair of electrodes and an EL layer between the pair of electrodes, a delayed fluorescence component due to triplet-triplet annihilation accounts for 20% or more of light emitted from the EL layer, and the light has at least one emission spectrum peak in the blue wavelength range. The EL layer includes an organic compound in which an energy difference between the lowest singlet excited energy level and the lowest triplet excited energy level is 0.5 eV or more. The EL layer includes a benzo[a]anthracene compound.

A novel display apparatus that is highly convenient, useful, or reliable is provided. The display apparatus includes a first electrode, a second electrode, a first unit, a second unit, and a first intermediate layer; the first unit is located between the second electrode and the first electrode; and the first unit contains a first light-emitting material EM1. The second unit is located between the second electrode and the first unit and contains a second light-emitting material EM2. The first intermediate layer is located between the second unit and the first unit. The first intermediate layer includes a first layer and a second layer; the first layer is located between the second unit and the second layer; the first layer contains an organic compound having a halogen group or a cyano group or a transition metal oxide; and the second layer contains a first organic compound AM2 having an electron-accepting property, a second organic compound DM having an electron-donating property, and a third organic compound BM having basicity.

A photoelectric device includes a first electrode, a second electrode, a photoelectric conversion layer between the first electrode and the second electrode, and a charge transport layer between the first electrode and the photoelectric conversion layer. The photoelectric conversion layer is configured to absorb light in a wavelength spectrum and converting the absorbed light into an electrical signal. The charge transport layer includes a first charge transport material and a second charge transport material which collectively define a heterojunction.

An organic electroluminescent device is disclosed. The organic electroluminescent device achieves low driving voltage and high luminous efficiency as well as long lifespan by including an exciton confinement layer (ECL), in which a predetermined physical property is adjusted, in an area of an electron transporting area, including at least two layers, that is adjacent to an emissive layer.

The present disclosure relates to a plurality of host materials comprising a first host material comprising a compound represented by formula 1, and a second host material comprising a compound represented by formula 2, and an organic electroluminescent device comprising the same. By comprising a specific combination of compounds of the present disclosure as host materials, it is possible to provide an organic electroluminescent device having higher luminous efficiency and/or longer lifetime properties as compared with a conventional organic electroluminescent device.