A light-emitting device includes an electron transport layer, and the electron transport layer include a mixture of a first material, a second material, and a third material, wherein the first material includes an electron transport compound, the second material includes a metal-containing material, and the third material includes a low-refractive-index compound. An electronic apparatus including the light-emitting device is also provided.

The present invention relates to a polycyclic aromatic derivative compound that can be employed in an organic layer in a device, and an organoelectroluminescent device with high-efficiency and a long-life, including same and having remarkably improved luminous efficiency, and the device employing same can be efficiently utilized in a variety of displays and lighting devices, such as a flat panel display device, a flexible display device, a single color or white flat lighting device, and a single color or white flexible lighting device.

Provided are a compound of Formula 1 and an organic electric element including a first electrode, a second electrode, and an organic material layer between the first electrode and the second electrode and comprising the compound, the element showing improved luminescence efficiency, stability, and life span.

The present disclosure describes an electroluminescent material which is formed of a compound having a structure of Formula (I), an OLED display panel utilizing the compound and an electronic device having the OLED display panel. The OLED display panel includes a first electrode, a second electrode, and an organic thin film layer disposed between the first electrode and the second electrode. The organic thin film layer comprises an electron transport layer which comprises any one or a combination of at least two of the compounds. The electroluminescent material has a triplet energy level E.sub.T of ≥2.7 eV, a HOMO energy level of ≤−5.85 eV, and a glass transition temperature of >120° C. This compound improves luminous efficiency in the OLED display panel and the electronic device.

A light-emitting element whose degree of deterioration with driving time is improved and of which emission colors are easily controlled. A light-emitting emitting element having a first electrode, a second electrode, and a layer containing an organic compound located between the first electrode and the second electrode, in which the layer containing the organic compound at least has, from the second electrode side, a light-emitting layer in which a first layer, a second layer, and a third layer are stacked, and a hole-transporting layer provided in contact with the third layer; the first layer contains a first organic compound and a second organic compound; the second layer contains a third organic compound and a fourth organic compound; and the third layer contains the first organic compound and a fifth organic compound.

An organometallic compound represented by Formula 1, a light-emitting device including the organometallic compound, and an electronic apparatus including the light-emitting device. In Formula 1, the substituents are the same as described in the Detailed Description.

##STR00001##

An organic light-emitting device includes a mixed layer, an emission layer, and a buffer layer and satisfies one of Equation 1 or Equation 2 and Equation 3:
T1(D)≥T1(Mix)+0.3 eV  Equation 1
T1(H)≥T1(Mix)+0.3 eV  Equation 2
T1(Mix)<T1(Buffer)+0.5 eV.  Equation 3

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a π complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or ≥1; is the number of ligands K, where o can be 0 or ≥1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

An organic light emitting device including an emissive layer including a blue phosphorescent emitter, an electron transport layer, and a hole blocking layer between the emissive layer and the electron transport layer, wherein the hole blocking layer comprises a tetradentate palladium complex.

An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, an organic layer between the first electrode and the second electrode and including an emission layer, and at least one of a first layer and a second layer, wherein the first layer is positioned in a path where light generated in the emission layer is transmitted to the outside through the first electrode and the second layer is positioned in a path where the light generated in the emission layer is transmitted to the outside through the second electrode. The first layer and the second layer each include a compound having a certain formula and absorbing external ultraviolet rays to prevent or reduce the ultraviolet (UV) rays from transmitting therethrough.