A light emitting diode of an embodiment includes a first electrode, a second electrode, and at least one functional layer between the first electrode and the second electrode, wherein the at least one functional layer includes at least one selected from among a polycyclic compound represented by Formula 1 and a compound represented by Formula E-1.

##STR00001##

Provided are organometallic compounds comprising a first ligand L.sub.A comprising a multicyclic fused ring system wherein ligand L.sub.A is coordinated to a metal M; and wherein M is selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag, and Au. Also provided are formulations comprising these compounds. Further provided are OLEDs and related consumer products that utilize these compounds.

A light emitting element that includes a first compound represented by a specific chemical formula in which an ortho-type or kind penta-phenyl group is bonded to a fused polycyclic compound including at least one boron atom and a heteroatom is provided. The light emitting element has a long-lifetime.

Disclosed are a light emitting device that includes an additional layer adjacent to a light emitting layer and thus is capable of utilizing, in light emission, holes not used in the light emitting layer, to improve efficiency and lifespan, and a light emitting display device including the same. The light emitting device includes a first electrode and a second electrode facing each other, and an unit comprising a hole transport layer, a light emitting layer, an efficiency-improving layer, and an electron transport layer sequentially stacked between the first electrode and the second electrode, wherein the light emitting layer includes a first host comprising an anthracene derivative and a first blue light emitting dopant, and the efficiency-improving layer includes a second host having bipolarity and a second blue light emitting dopant.

Provided is an organic electroluminescent device. The organic electroluminescent device is a blue delayed fluorescent device including an anode, a cathode, an emissive layer disposed between the anode and the cathode and a hole blocking layer disposed between the emissive layer and the cathode, where the hole blocking layer comprises a hole blocking material having a structure of Formula 1, and the emissive layer comprises a first host material, a second host material and a blue delayed fluorescent material having a structure of Formula 3. The blue delayed fluorescent device exhibits excellent overall device performance, such as higher efficiency and longer lifetime. Further provided are a light-emitting device comprising a blue delayed fluorescent unit, a green phosphorescent unit and a red phosphorescent unit and a display assembly comprising the blue delayed fluorescent device and the light-emitting device.

The present invention relates to a compound, a display panel and a display device. The compound has a structure represented by Formula I. The compound takes a spiro structure as a non-conjugated connecting unit, and a boron-containing group as an electron-accepting group. A light-emitting compound obtained by taking the group as a building block has a narrower half-peak width and higher color purity. The boron-containing spiro structure is connected with an electron-donating group to obtain a bipolar compound, and as a thermal activation delay fluorescence material, the bipolar compound can be used a light-emitting layer material, particularly a doped material, and can also be used as a fluorescent host material or a phosphorescent host material. The compound provided herein can achieve low drive voltages and high luminescence efficiencies when applied to organic electroluminescent devices.

The present disclosure relates to a plurality of host materials comprising a first host material including a compound represented by formula 1 and a second host material including a compound represented by formula 2, and an organic electroluminescent device comprising the same. In addition, the present disclosure relates to an organic electroluminescent compound, and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound and/or a specific combination of compounds according to the present disclosure as host materials, an organic electroluminescent device having high luminous efficiency and long lifespan property can be provided.

In one aspect, provided is a compound of Formula I,

##STR00001##

In Formula I, M is Pt or Pd; L has the structure

##STR00002##

F.sub.1 is

##STR00003##

or a direct bond; rings A, B, C, D, and F are independently monocyclic rings or multicyclic fused ring systems; each of X.sup.1 to X.sup.10 is independently C or N; each of Z.sup.1 to Z.sup.4 is C or N; each of L.sup.1 to L.sup.5 is a direct bond or an organic linker; each of a, b, c, and d is 0 or 1; each K.sup.1 to K.sup.4 is a direct bond, O, or S; each of Z.sup.1 to Z.sup.4 that is connected to O or S is C; and each R.sup.A, R.sup.B, R.sup.C, R.sup.D, R.sup.E, and R.sup.X is independently hydrogen or a substituent.

Provided are a polycyclic compound represented by Formula 1, an organic light-emitting device including the polycyclic compound, and an electronic apparatus including the organic light-emitting device:

##STR00001##

Formula 1 may be understood by referring to the description of Formula 1 provided herein.

Provided are a family of chromophores including naphthyl or naphthyl-like carbocyclic or heterocyclic rings as luminescent dyes that can be useful as emitters in OLEDs. These compounds have Formula I,

##STR00001##

Also provided are formulations including these inventive compounds. Further provided are OLEDs and related consumer products that utilize these inventive compounds.