A display apparatus includes: a substrate; a pixel electrode above the substrate; a first low reflection layer spaced apart from the pixel electrode at a same layer as the pixel electrode and comprising a lower layer having conductivity and an upper layer above the lower layer; a pixel-defining layer above the first low reflection layer and having an opening exposing at least a part of the pixel electrode; an intermediate layer above the pixel electrode and comprising an organic emission layer; and an opposite electrode above the intermediate layer.

To provide an organic electroluminescent device in which energy efficiency is improved. An organic electroluminescent device includes a pair of electrode layers formed of an anode layer and a cathode layer, and a luminescent layer arranged between the pair of electrode layers, in which the luminescent layer includes a host material and a dopant material, and the dopant material is an anthracene-based compound represented by formula (1), and the luminescent layer further includes a polycyclic aromatic compound represented by formula (2) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by formula (2). ##STR00001##

To provide an organic electroluminescent device in which energy efficiency is improved. An organic electroluminescent device includes a pair of electrode layers formed of an anode layer and a cathode layer, and a luminescent layer arranged between the pair of electrode layers, in which the luminescent layer includes a host material and a dopant material, and the dopant material is an anthracene-based compound represented by formula (1), and the luminescent layer further includes a polycyclic aromatic compound represented by formula (2) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by formula (2). ##STR00001##

An organic electroluminescence device includes: a first emitting layer including a first host material, a first organic material, and a first dopant material; and a second emitting layer including a second host material and a second dopant material, in which the first host material, the first organic material, and the second host material are different compounds in structure and satisfy Numerical Formula 1 and Numerical Formula 2. Numerical Formula 1: T.sub.1(H1)>T.sub.1(H3), Numerical Formula 2: T.sub.1(H2)>T.sub.1(H3) (In Numerical Formula 1 and Numerical Formula 2, T.sub.1(H1), T.sub.1(H2), T.sub.1(H3) are triplet energies of the first host material, the first organic material, and the second host material, respectively.)

An organic electroluminescence device includes: a first emitting layer including a first host material, a first organic material, and a first dopant material; and a second emitting layer including a second host material and a second dopant material, in which the first host material, the first organic material, and the second host material are different compounds in structure and satisfy Numerical Formula 1 and Numerical Formula 2. Numerical Formula 1: T.sub.1(H1)>T.sub.1(H3), Numerical Formula 2: T.sub.1(H2)>T.sub.1(H3) (In Numerical Formula 1 and Numerical Formula 2, T.sub.1(H1), T.sub.1(H2), T.sub.1(H3) are triplet energies of the first host material, the first organic material, and the second host material, respectively.)

The present disclosure relates to a boron compound applicable to an organic light-emitting diode and an organic light-emitting diode comprising same. More specifically, the present disclosure relates to a boron compound represented by any one of Chemical Formulas A to D and an organic light-emitting diode comprising same, wherein Chemical Formulas A to D are as defined in the description.

Provided is an organic light emitting device including an anode; a cathode; a light emitting layer between the anode and the cathode; a first organic material layer between the light emitting layer and the anode; and a second organic material layer between the light emitting layer and the cathode, wherein the first organic material layer comprises a compound of Chemical Formula 1, the light emitting layer comprises a compound of Chemical Formula 2, the second organic material layer comprises a compound of Chemical Formula 3, and Chemical Formula 1 and Chemical Formula 3 satisfy one or more of <Equation 1> to <Equation 3>:

##STR00001##

|E.sub.L1|<E.sub.L3|  <Equation 1>

E.sub.s1>E.sub.s3  <Equation 2>

E.sub.T1>E.sub.T3  <Equation 3>

Provided are organometallic compounds. Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.

Provided is a cross-linkable arylamine-based compound represented by Formula 1a or 1b, a polymer obtained therefrom, a light-emitting device including the polymer, and an electronic apparatus including the light-emitting device. The light-emitting device includes a first electrode; a second electrode facing the first electrode; and an intermediate layer between the first electrode and the second electrode and comprising an emission layer, wherein the intermediate layer includes at least one of the arylamine-based polymer formed by cross-linking a cross-linkable arylamine-based compound represented by Formula 1a or 1b.