A compound comprising a first ligand L.sub.A of Formula I or Formula II: ##STR00001## wherein A.sup.1 and A.sup.2 are each independently C or Si; wherein each R.sup.A, and R.sup.B independently represents mono to the maximum allowable substitution, or no substitution; wherein each X.sup.1, X.sup.2, and X.sup.3 is independently C or N; wherein each R, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.A is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein L.sub.A is complexed to a metal M; wherein M is optionally coordinated to one or more other ligands; wherein the ligand L.sub.A is optionally linked with the one or more other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand; and wherein any two substituents are optionally joined or fused together to form a ring.

Provided is a compound of Formula 1:

##STR00001## Ar.sub.1 to Ar.sub.1 are each independently hydrogen, deuterium, a halogen group, a nitrile group, or a substituted or unsubstituted: silyl, boron, alkyl, alkenyl, alkynyl, alkoxy, aryloxy, cycloalkyl, aryl, or heterocyclic group, or adjacent groups are bonded together to form a substituted or unsubstituted aliphatic hydrocarbon ring; A1 and A2 are each independently hydrogen, deuterium, a halogen group, a nitrile group, or a substituted or unsubstituted: silyl, boron, alkyl, alkenyl, alkynyl, alkoxy, aryloxy, cycloalkyl, aryl, or heterocyclic group, or are bonded together to form a substituted or unsubstituted ring; R.sub.1 to R.sub.3 are each independently hydrogen, deuterium, a halogen group, a nitrile group, or a substituted or unsubstituted; silyl, boron, alkyl, alkenyl, alkynyl, alkoxy, aryloxy, cycloalkyl, aryl, amine, or heterocyclic group; and n1 to n3 are each 0 to 3, and 2 or more, the substituents are the same as or different from each other,
and an organic light emitting device including the same.

The present disclosure provides an organic electroluminescent device including: an anode; a cathode; and one or more organic material layers interposed between the anode and cathode and selected from the group consisting of a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injection layer, and further including a lifetime enhancement layer (LEL) between the light emitting layer and the electron transporting layer.

A novel light-emitting device is provided. A light-emitting device with high emission efficiency is provided. A light-emitting device with along lifetime is provided. A light-emitting device with low driving voltage is provided. The light-emitting device includes an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes a hole-injection layer, a light-emitting layer, and an electron-transport layer. The hole-injection layer is positioned between the anode and the light-emitting layer. The electron-transport layer is positioned between the light-emitting layer and the cathode. The hole-injection layer contains a first substance and a second substance. The first substance is an organic compound which has a hole-transport property and a HOMO level higher than or equal to −5.7 eV and lower than or equal to −5.4 eV. The second substance exhibits an electron-accepting property with respect to the first substance. The electron-transport layer contains a material whose resistance decreases with current flowing therethrough.

Disclosed herein are a white organic light-emitting device. The white organic light-emitting device enables an overall improvement in characteristics such as color temperature, efficiency, luminance, and service life, by changing the configuration of different types of emission layers in contact with each other, and a display device using the same.

Provided are a light-emitting device and an electronic apparatus including the same, the light-emitting device including: a first electrode; a second electrode facing the first electrode; and an emission layer between the first electrode and the second electrode. The emission layer includes i) a first emission layer and ii) a second emission layer located between the first emission layer and the second electrode, the first emission layer is in direct contact with the second emission layer, the first emission layer includes a dopant, a first hole-transporting compound, and a first compound, the second emission layer includes a dopant, a second hole-transporting compound, and a second compound, the dopant included in the first emission layer and the dopant included in the second emission layer are identical to each other, the first compound and the second compound are different from each other, and an absolute value of the difference between a HOMO energy level of the second hole-transporting compound and a HOMO energy level of the second compound is about 0.3 eV or less.

Provided are a light-emitting device and an electronic apparatus including the light-emitting device. The light-emitting device may include: an emission layer between a first electrode and a second electrode. The emission layer may include i) a first emission layer and ii) a second emission layer between the first emission layer and the second electrode, the first emission layer may be in direct contact with the second emission layer, the first emission layer may include a first dopant, a first hole-transporting compound, and a first electron-transporting compound, the second emission layer may include a second dopant, a second hole-transporting compound, and a second electron-transporting compound, the first dopant may be identical to the second dopant, and the first electron-transporting compound may be different from the second electron-transporting compound, electron mobility of the second electron-transporting compound may be greater than electron mobility of the first electron-transporting compound.

Provided are an organic electroluminescent device, a display panel, and a display apparatus. An exciton layer adjacent to a light-emitting layer is added, and the exciton layer serves as an exciton recombination region and achieves the effect of increasing the density of excitons, where the singlet-state energy level of the exciton layer is higher than the singlet-state energy level of a host material in the light-emitting layer, and an emission spectrum of the exciton layer and an absorption spectrum of the host material in the light-emitting layer have an overlapping area. Moreover, the exciton layer allows triplet-state excitons formed in the exciton layer to form singlet-state excitons via a reverse intersystem crossing process.

An organic light emitting device (OLED) architecture in which efficient operation is achieved for the OLED having three hosts in the emissive layer by incorporating at least one multi-component functional layer selected from the group consisting of a hole injecting layer, a hole transporting layer, an electron blocking layer, a hole blocking layer, an electron transporting layer, and an electron injecting layer.

A novel organic compound that is highly convenient, useful, or reliable is provided. The organic compound is represented by General Formula (G1). Note that at least one of R.sup.1 to R.sup.26 represents deuterium. At least one of R.sup.1 to R.sup.7 represents any one of an alkyl group, a cycloalkyl group, a trialkylsilyl group, and an aryl group. The others of R.sup.1 to R.sup.7 each independently represent any one of hydrogen, an alkyl group, a cycloalkyl group, a trialkylsilyl group, and an aryl group. R.sup.8 to R.sup.26 each independently represent any one of hydrogen, an alkyl group, a cycloalkyl group, a trialkylsilyl group, and an aryl group. The alkyl group has 3 to 10 carbon atoms, the cycloalkyl group has 3 to 10 carbon atoms, the trialkylsilyl group has 3 to 12 carbon atoms, and the aryl group has 6 to 25 carbon atoms.