Provided is an organic electroluminescence device including a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The hole transport region includes a first hole transport layer disposed adjacent to the first electrode, the first hole transport layer including a first organic compound having a first dielectric constant and a second hole transport layer disposed between the first hole transport layer and the emission layer, the second hole transport layer including a second organic having a second dielectric constant which is greater than the first dielectric constant.

A composition, an OLED device and an OLED display panel. The composition includes a low-mobility metal complex material of bias-electron-transport-type in a mass percentage of 1% to 99% and an organic electron transport material in a mass percentage of 1% to 99%, wherein an electron mobility of the low-mobility metal complex material of bias-electron-transport-type is less than 1*E.sup.−7 cm.sup.2/Vs. The influence of the electric field and the temperature on the electron mobility in the electron transport layer can be reduced, the balance of a carrier system in a high temperature environment is better, and the service life in the high temperature environment is long.

An organic EL device includes an anode, a cathode, and an emitting layer. The emitting layer contains a first compound represented by a formula (1X) or a formula (1Y), a second compound, and a third compound that exhibits delayed fluorescence. The second compound is different in structure from the first compound. The second compound is different in structure from the third compound. Singlet energies S.sub.1 of the first, second, third compounds satisfy Numerical Formula 1 and Numerical Formula 2 below,

##STR00001##

A is, for example, a group represented by a formula (a1); Y.sub.11˜Y.sub.13 are, for example, each independently a nitrogen atom or CRy; Ry is, for example, a substituent or a group represented by a formula (1Z); R.sub.1X to R.sub.3X are, for example, each independently a substituent or a group represented by a formula (1Z).

By introducing new concepts into a structure of a conventional organic semiconductor element and without using a conventional ultra thin film, an organic semiconductor element is provided which is more reliable and has higher yield. Further, efficiency is improved particularly in a photoelectronic device using an organic semiconductor. Between an anode and a cathode, there is provided an organic structure including alternately laminated organic thin film layer (functional organic thin film layer) realizing various functions by making an SCLC flow, and a conductive thin film layer (ohmic conductive thin film layer) imbued with a dark conductivity by doping it with an acceptor and a donor, or by the like method.

An organic light-emitting device and an electronic apparatus incorporating the same. The organic light-emitting device includes an anode, a cathode, and an organic layer between the anode and the cathode and comprising an emission region. The emission region includes a first emission layer, a second emission layer, and a first exciton quenching layer. The first emission layer comprises a first host and a first dopant, the second emission layer comprises a second host and a second dopant, and the first exciton quenching layer is disposed between the first emission layer and the second emission layer and comprises a first quenching material.

One embodiment of the present invention provides an organic semiconductor material for electron transport. The organic semiconductor material for electron transport may have a structure represented by the following Formula 1: ##STR00001## wherein X.sup.1 and X.sup.2 each independently represent oxygen (O) or sulfur (S) and R.sup.1 and R.sup.2 each may independently contain a pyridine group, a dipyridylbenzene group, a fluoropyridine group, a diphenylthiazole group, a diphenyloxazole group, a triphenyldiazole group, a phenylthiadiazole group, a phenyloxadiazole group, a diphenyltriazole group, a pyrimidine group, a pyrimidylbenzene group, a phenylpyrimidine group, a diphenylphosphine oxide group, a diphenyltriazine group or a phenyltetrazine group.

A light-emitting device with low driving voltage and favorable reliability is provided. The light-emitting device includes an electron-injection layer between a cathode and a light-emitting layer. The electron-injection layer is a mixed film of a metal and an organic compound having a function of interacting with the metal as a tridentate or tetradentate ligand, and the metal atom and the organic compound form SOMO.

Disclosed is an organic electroluminescent device, comprising a substrate and light emitting units formed in sequence on the substrate, characterized in that, each of the light emitting units comprises a first electrode layer (1), a light emitting layer (2) and a second electrode layer (3), the light emitting layer comprises a host material and a dye, the host material is made of materials having both electron transport capability and hole transport capability; at least one material in the host material has a CT excited triplet state energy level T.sub.1 greater than its n-π excited triplet state energy level S.sub.1, and T.sub.1-S.sub.1≤0.3 eV; or, at least one material in the host material has a CT excited triplet state energy level T.sub.1 greater than its n-π excited triplet state energy level S.sub.1, and T.sub.1-S.sub.1≥1 eV, with the difference between its n-π excited second triplet state energy level and its CT excited first singlet state energy level being in the range of −0.1 eV to 0.1 eV. The organic electroluminescent device configuration can sufficiently utilize the triplet state energy in the host material and the dye to increase the luminous efficiency and prolong the service life of the device.

Provided is an organic electroluminescent element having high efficiency, a long lifetime, and bending resistance. An organic electroluminescent element includes a light emitting layer and an electron transport layer adjacent to the light emitting layer between a positive electrode and a negative electrode. A host compound of the light emitting layer has an ionization potential deeper than that of a light emitting dopant of the light emitting layer by 0.3 eV or more. At least one organic compound contained in the electron transport layer has a molecular dipole moment of 6.0 debye or more.

A light emitting device having an anode, a cathode, a first organic layer and a second organic layer disposed between the anode and the cathode is provided. The first organic layer is a layer containing a light emitting material represented by the formula (T) and the second organic layer is a layer containing a crosslinked body of a polymer compound containing a crosslink constitutional unit wherein the variable groups are as defined in the specification: ##STR00001##