Provided is an organic light-emitting element that is excited by an electromagnetic wave. The organic light-emitting element includes: a first electrode; a second electrode disposed to face the first electrode; an organic light-emitting layer disposed between the first electrode and the second electrode, where separation of charges occurs due to incidence of the electromagnetic wave; a hole transporting layer disposed between the first electrode and the organic light-emitting layer; and a charge block layer disposed between the second electrode and the organic light-emitting layer. The charge block layer has a LUMO level shallower than a LUMO level of organic light emitters included in the organic light-emitting layer.

An electroluminescent device comprising a first electrode and a second electrode facing each other, an emission layer disposed between the first electrode and the second electrode and including at least two light emitting particles, a hole transport layer disposed between the first electrode and the emission layer, and an electron transport layer disposed between the emission layer and the second electrode, wherein the electron transport layer comprises an inorganic layer disposed on the emission layer, the inorganic layer comprising a plurality of inorganic nanoparticles; and an organic layer directly disposed on at least a portion of the inorganic layer on a side opposite the emission layer, wherein a work function of the organic layer is greater than a work function of the inorganic layer.

An organic light-emitting device and display apparatus, the device including a first electrode; a second electrode facing the first electrode; an emission layer between the first and second electrode; a hole control layer between the first electrode and the emission layer; and an electron control layer between the emission layer and the second electrode, wherein the emission layer includes a plurality of sub-emission layers to emit light having different wavelengths, at least portions of the plurality of sub-emission layers do not overlap one another, the plurality of sub-emission layers include: a first sub-emission layer including a first color light-emitting dopant, and a second sub-emission layer including a second color light-emitting dopant, the first and second sub-emission layers each include a hole-transporting and electron-transporting host which form an exciplex, and a triplet energy of the exciplex is equal to or greater than triplet energies of the first and second color light-emitting dopant.

A heterocyclic compound represented by Chemical Formula 1 and an organic light emitting device including the same, and the heterocyclic compound which is used as a material of an organic material layer of the organic light emitting device and provides improved efficiency, low driving voltage and improved lifetime characteristics of the organic light emitting device.

##STR00001##

The present invention provides an organic electroluminescent device, a display panel, and a display apparatus. A light-emitting layer comprises a first compound, a second compound, a third compound, and a fourth compound; the first compound and the second compound form a first exciplex under optical excitation and electric excitation; excitonic energy compounded by the first exciplex can be transferred to the third compound; then the third compound and the second compound are compounded to form a second exciplex; and excitonic energy compounded by the second exciplex can be transferred to the fourth compound. In the excitonic energy transfer process, triplet excitons improve a reverse intersystem crossing process and are converted into singlet excitons to radiate and emit fluorescence when an exciplex is formed by means of compounding; the singlet excitons are effectively used for Forster energy transfer, and Dexter energy transfer is inhibited, such that energy loss is avoided, the excitonic energy is effectively used, and the device efficiency is improved.

An imaging device includes pixels. Each of the pixels includes a first electrode, a second electrode, a photoelectric conversion layer that is located between the first electrode and the second electrode, that contains a donor semiconductor material and an acceptor semiconductor material, and that generates a pair of an electron and a hole, a first charge blocking layer located between the first electrode and the photoelectric conversion layer, a second charge blocking layer located between the second electrode and the photoelectric conversion layer, and a charge storage region that is electrically connected to the second electrode and that stores the hole. The difference between the electron affinity of the acceptor semiconductor material and the electron affinity of the first charge blocking layer is larger than the difference between the ionization potential of the donor semiconductor material and the ionization potential of the second charge blocking layer.

An organic electroluminescence device comprising: a cathode; an anode; an emitting layer disposed between the cathode and the anode; and a first layer disposed between the emitting layer and the cathode, wherein the emitting layer comprises a host compound, the first layer comprises a first compound and a second compound, and the three compounds are in a relationship satisfying the following Conditions 1 and 2: (Condition 1) the electron affinity Af.sub.H of the host compound and the electron affinity Af.sub.ETA of the first compound satisfy the following expressions (1-1) and (1-2):

Af.sub.H<Af.sub.ETA  (1-1)

|Af.sub.H−Af.sub.ETA|≤0.10  (1-2) (Condition 2) the electron affinity Af.sub.H of the host compound and the electron affinity Af.sub.ETB of the second compound satisfy the following expressions (2-1) and (2-2):

Af.sub.H>Af.sub.ETB  (2-1)

|A.sub.fH−Af.sub.ETB|≤0.10  (2-2).

The present disclosure provides an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and an emitting material layer. The emitting material layer includes a p-type host, a n-type host and a phosphorescent dopant and positioned between the first electrode and the second electrode, wherein a first energy level of a HOMO of the p-type host is equal to or lower than a second energy level of a HOMO of the n-type host, and a difference between an energy level of a singlet state of the n-type host and an energy level of a triplet state of the n-type host is greater than 0.3 eV and smaller than 0.5 eV.

An organic electric element according to an embodiment of the present disclosure includes a first electrode, a second electrode, and an organic material layer formed between the first electrode and the second electrode. The organic material layer includes a plurality of emission-auxiliary layers, and the HOMO energy levels of the plurality of emission-auxiliary layers are limited to specific conditions in relation to the neighboring organic material layers, thereby the driving voltage, the luminous efficiency and the life time of the organic electric element can be improved.

The present disclosure relates to compounds of Formula (I), (II), or (III) ##STR00001## as compounds capable of emitting delayed fluorescence, and uses of these compounds in organic light-emitting diodes.