A light emitting element includes a first electrode, a second electrode, and an emission layer between the first electrode and the second electrode and includes a compound represented by Formula 1 below, thereby exhibiting a long service life characteristic.

##STR00001##

Embodiments provide an organometallic compound, a light-emitting device including the organometallic compound, and an electronic apparatus including the light-emitting device. The light-emitting device includes a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and the organometallic compound, which is represented by Formula 1.

##STR00001##

The description of Formula 1 is provided in the specification.

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

##STR00001##

wherein the detailed description of Formula 1 is the same as described in the specification.

An organic electronic element, a display panel and a display device can each include a charge generating layer and a hole injection layer including a p-type dopant with low absorption rate for a blue wavelength band so that they can have excellent light extraction efficiency or luminous efficiency.

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.

A light emitting element that includes a first electrode, a second electrode on the first electrode, an emission layer between the first electrode and the second electrode, and a hole transport region which is between the first electrode and the emission layer is provided. The emission layer includes an amine compound represented by Formula 1:

##STR00001##

An organic light emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer, wherein the organic layer includes a first compound, a second compound, a third compound, and a fourth compound, and the first compound to the fourth compound satisfy Equations 1 to 8:
E.sub.1,LUMO≥E.sub.2,LUMO+0.15 electron volts (eV)  Equation 1
E.sub.1,HOMO≥E.sub.2,HOMO+0.15 eV  Equation 2
E.sub.1,T1≥E.sub.4,T1  Equation 3
E.sub.2,T1≥E.sub.4,T1  Equation 4
E.sub.3,T1≥E.sub.4,T1  Equation 5
E.sub.3,LUMO≥E.sub.2,LUMO+0.1 eV  Equation 6
−5.6 eV≥E.sub.3,HOMO  Equation 7
E.sub.gap1≥E.sub.gap3.  Equation 8

The purpose of the present invention is to provide: a π-conjugated compound exhibiting excellent light emission characteristics; an organic electroluminescent element using same; a display device; and an illumination device. Accordingly, this organic electroluminescent element is provided with: a positive electrode; a negative electrode; and at least one organic layer which is sandwiched between the positive electrode and the negative electrode, and which includes a light emission layer. The light emission layer includes a π-conjugated compound having a structure represented by any of general formulae (1)-(3) ##STR00001##
(in general formulae (1)-(3), at least one among R1-R4, R5-R8, and R9-R16 represents a group represented by general formula (4) ##STR00002##
(in general formula (4): Ar1 and Ar2 represent substituted or unsubstituted aryl groups; L1 represents a single bond or a substituted or unsubstituted arylene group; and # represents a bond to general formulae (1)-(3))).

The present disclosure provides a novel compound and an organic light-emitting device comprising the same. When the novel compound is applied as a hole transport material to an organic light emitting device, the novel compound allows the device to have improved drive voltage, efficiency and lifespan characteristics.

A novel compound having a benzimidazole based structure is disclosed that is selected from one of the following structures: ##STR00001##
The compound is useful in improving photophysical performance of OLEDs.