Embodiments provide a heterocyclic compound, a light-emitting device that includes the heterocyclic compound, and an electronic apparatus that includes the light-emitting device. The light-emitting device includes a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and at least one of the heterocyclic compound. The heterocyclic compound is represented by Formula 1, which is explained in the specification:

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Provided is an organic light emitting device including an anode; a cathode; a light emitting layer between the anode and the cathode; a first organic material layer between the light emitting layer and the anode; and a second organic material layer between the light emitting layer and the cathode, wherein the first organic material layer comprises a compound of Chemical Formula 1, the light emitting layer comprises a compound of Chemical Formula 2, the second organic material layer comprises a compound of Chemical Formula 3, and Chemical Formula 1 and Chemical Formula 3 satisfy one or more of <Equation 1> to <Equation 3>:

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|E.sub.L1|<E.sub.L3|  <Equation 1>

E.sub.s1>E.sub.s3  <Equation 2>

E.sub.T1>E.sub.T3  <Equation 3>

Disclosed are a heterocyclic compound represented by Formula 1-1 or 1-2,

##STR00001## wherein, in Formulae 1-1 and 1-2, X.sub.1, CY.sub.1 to CY.sub.3, R.sub.1 to R.sub.3, and a1 to a3, are the same as described in the specification. Also disclosed is an organic light-emitting device including the same.

A display apparatus, comprising a substrate; a light-emitting device layer arranged on the substrate, wherein the light-emitting device layer comprises a first, second, and third areas, and at least one light-emitting device emitting a first light; and a color conversion layer arranged on the light-emitting device layer, wherein the color conversion layer comprises first, second, and third color conversion areas, wherein the first color conversion area emits a first color light, the second color conversion area emits a second color light, the third color conversion area emits a third color light, a maximum emission wavelength of the first, second, and third color lights are greater than a maximum emission wavelength of the first light, a color of the third color light is identical to that of the first light, and the maximum emission wavelength of the third color light is greater than the maximum emission wavelength of the first light.

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.

A novel light-emitting element is provided. A light-emitting element with a long lifetime is provided. A light-emitting element with high emission efficiency is provided. In the light-emitting element, an EL layer includes a hole-injection layer, a first hole-transport layer, a second hole-transport layer, a third hole-transport layer, a light-emitting layer, a first electron-transport layer, and a second electron-transport layer in this order; the hole-injection layer includes an organic acceptor; the LUMO level of the host material is higher than that of the first electron-transport layer; the LUMO level of the second electron-transport layer is higher than that of the first electron-transport layer; the host material is a substance including a condensed aromatic ring skeleton; and the first and second electron-transport layers each include a substance having a heteroaromatic ring skeleton.

The present invention provides a photoelectric conversion element having excellent heat resistance. In addition, the present invention provides an optical sensor and an imaging element including the photoelectric conversion element. In addition, the present invention provides a compound applied to the photoelectric conversion element. The photoelectric conversion element according to the embodiment of the present invention including a conductive film, a photoelectric conversion film, and a transparent conductive film, in this order, in which the photoelectric conversion film contains a compound represented by Formula (1) or (2). ##STR00001##

An organic light-emitting device includes: a first pixel electrode on a first emission region, a second pixel electrode on a second emission region, and a third pixel electrode on a third emission region; a counter electrode facing each of the first pixel electrode, the second pixel electrode, and the third pixel electrode; and an interlayer between the counter electrode and each of the first pixel electrode, the second pixel electrode, and the third pixel electrode. The interlayer includes an emission layer, and a hole transport region between the emission layer and each of the first pixel electrode, the second pixel electrode, and the third pixel electrode, the hole transport region includes a planarization layer that includes an amine-based compound represented by Formula 1, Formula 2A, or Formula 2B, and the amine-based compound has a crystallization peak having a noise-to-peak ratio of 1.75 or more in an X-ray diffraction (XRD) spectrum.

Provided are an organic electric element comprising as a phosphorescent host material, a mixture of the compounds of Formula (1) and Formula (2), and an organic electronic device or apparatus thereof for achieving a high luminous efficiency, a low driving voltage, and an improved lifespan.

Provided are compounds, formulations comprising compounds, and devices that utilize compounds, where the devices include a substrate, a first electrode, an organic emissive layer comprising an organic emissive material disposed over the first electrode. The device includes an enhancement layer, comprising a plasmonic material exhibiting surface plasmon resonance that non-radiatively couples to the organic emissive material and transfers excited state energy from the organic emissive material to the non-radiative mode of surface plasmon polaritons. The enhancement layer is provided no more than a threshold distance away from the organic emissive layer, where the organic emissive material has a total non-radiative decay rate constant and a total radiative decay rate constant due to the presence of the enhancement layer. At least one of the organic emissive material and the organic emissive layer has a vertical dipole ratio (VDR) value of equal or greater than 0.33.