The device provided herein is an organic electroluminescent device and includes a substrate; a first electrode on the substrate and with high reflectivity; a translucent or transparent second electrode over the first electrode; and a first, a second and a third organic layer included between the first and the second electrode; where the second organic layer has a thickness >80 nm and is made of a second organic material; the third organic layer is a light-emitting layer including at least one light-emitting material and at least one host material; the first organic layer has a conductivity >1×10.sup.−4 S/m and <1×10.sup.−2 S/m; an energy level difference between HOMO energy level of the second organic material and HOMO energy level of the at least one host material is <0.27 eV; and the first electrode and the second organic layer are in direct contact with the first organic layer.

The present disclosure provides a blue organic light-emitting diode. The blue organic light-emitting diode comprises a hole transport layer, a co-evaporation layer, a blue light-emitting auxiliary layer, a blue light-emitting layer, and an electron transport layer which are sequentially stacked. A material of the co-evaporation layer includes a mixture of a material of the hole transport layer and a material of the blue light-emitting auxiliary layer. The present disclosure also provides a display device. The display device has a good display effect under a low gray scale.

Provided is an electroluminescent device. The organic electroluminescent device comprises an anode, a cathode and an organic layer disposed between the anode and the cathode, where the organic layer comprises a first compound having a structure of H-L-E and a second compound comprising a ligand L.sub.a having a structure of Formula C. Such a new material combination consisting of the first compound and the second compound can obtain higher efficiency in the device, significantly extend a lifetime, and provide better device performance. Further provided are a display assembly comprising the electroluminescent device and a compound combination.

Provided is a compound of Formula I

##STR00001##

in which at least one moiety A, moiety B, moiety C, or moiety D is a 6-membered carbocyclic or heterocyclic ring, and at least one R.sup.A, R.sup.B, R.sup.C, or R.sup.D includes a group having Formula II

##STR00002##

where R.sup.X can be silyl, germyl, boryl, nitrile, F, CF.sub.3, cycloalkyl, heterocycloalkyl, or monocyclic heteroaryl. The compounds are useful as emitters in OLEDs providing improved efficiency.

A compound including a first ligand L.sub.A of Formula I,

##STR00001##

is described. In Formula I, each of X.sup.1 to X.sup.9 is independently C or N; one of Z.sup.1 and Z.sup.2 is C and the other is N; each of K.sup.1 and K.sup.2 is independently a direct bond, O, or S; at least one of K.sup.1 and K.sup.2 is a direct bond; at least one R.sup.B is not hydrogen; R.sup.3 is selected from alkyl, heteroalkyl, cycloalkyl, and heterocycloalkyl; L.sub.A is coordinated to a metal M; at least one of the following is true: (i) at least one R.sup.B comprises a 5- or 6-membered, (ii) two adjacent R.sup.B are joined to form a fused 5- or 6-membered ring, or (iii) R.sup.B comprises a carbocyclic or heterocyclic ring substituted with at least one electron withdrawing group. Devices, consumer products, and formulations including the compound are also described.

The present disclosure provides for an organic electroluminescent device (OLED) including an anode; a cathode; and an emissive layer, disposed between the anode and the cathode. The emissive layer includes a phosphorescent dopant, a first host, and a second host, wherein the first host transports holes, the second host transports electrons, and the first host is fully or partially deuterated. Consumer products that include the OLED are also provided.

An organic light-emitting device having improved efficiency and lifespan includes: a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer includes an emission layer, the emission layer includes a first compound, a second compound, a third compound, and a fourth compound, the first compound, the second compound, the third compound, and the fourth compound are different from each other, the third compound includes a metal element having an atomic number of 40 or more, the fourth compound includes boron (B), the third compound and the fourth compound each satisfy Conditions 1-1 and 1-2 below, and the fourth compound satisfies Condition 2 or 3:
T.sub.1(C3).sub.onset≥S.sub.1(C4).sub.onset  Condition 1-1
T.sub.1(C3).sub.max≥S.sub.1(C4).sub.max  Condition 1-2
K.sub.RISC(C4)≥10.sup.3S.sup.−1  Condition 2
f(C4)≥0.1.  Condition 3

The present disclosure features a luminescent molecule, including a luminophore (e.g., a fluorescent dye); and a moiety including a heteroaryl core covalently and directly bonded to the luminophore. The luminescent molecule has an increased photoluminescence quantum yield relative to an analogous luminophore without a covalently bonded moiety including the heteroaryl core.

Provided are an organic electroluminescent material and a device thereof. The organic electroluminescent material is a metal complex comprising a ligand L.sub.a having a structure of Formula 1. The metal complex may be used as a light-emitting material in an electroluminescent device. These novel compounds may be applied to electroluminescent devices and can exhibit better performance, achieve higher device efficiency, and significantly improve the overall performance of the devices. Further provided are an electroluminescent device comprising the metal complex and a compound combination comprising the metal complex.

Provided is an electroluminescent device. The organic electroluminescent device comprises an anode, a cathode and an organic layer disposed between the anode and the cathode, where the organic layer comprises a first compound having a structure of H-L.sub.1-E and a second compound having a general formula of M(L.sub.a).sub.m(L.sub.b).sub.n(L.sub.c).sub.q, and the device has at least one maximum emission wavelength greater than 630 nm. Such a new material composition consisting of the first compound and the second compound can be used in a light-emitting layer of the electroluminescent device. The new material composition can achieve the emission of deep red light in the device, significantly reduce a drive voltage of the device while significantly improving device efficiency and/or a device lifetime, and provide better device performance. Further provided is a display assembly.