An organic light-emitting device includes a heterocyclic compound represented by Formula 1 ##STR00001##
In Formula 1, X is O or S, one selected from R.sub.1 to R.sub.8 is a group represented by Formula 2-1, and one selected from the remaining groups is a group represented by Formula 2-2, wherein, when X is O, one selected from R.sub.1, R.sub.2, R.sub.4, R.sub.5, R.sub.7, and R.sub.8 is a group represented by Formula 2-1.

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##

The compound represented by formula (1):

##STR00001##

wherein symbols are as defined in the description, provides an organic electroluminescence device having a device performance further improved.

The compound represented by formula (1):

##STR00001##

wherein symbols are as defined in the description, provides an organic electroluminescence device having a device performance further improved.

Provided is an organic light emitting device including a light emitting layer comprising a compound of Chemical Formula 1 and a first organic material layer comprising a compound of Chemical Formula 2:

##STR00001## wherein: Cy1 to Cy5 are each independently one selected from among a substituted or unsubstituted: aromatic hydrocarbon ring, aliphatic hydrocarbon ring, and aromatic hetero ring, or a ring in which two or more rings selected from the above group are fused, one or more of Cy1 to Cy5 are a ring of Chemical Formula 1-A:

##STR00002## one to three of a* to d* are a position fused to or linked to Chemical Formula 1;

##STR00003## L1 to L3 are each independently a direct bond or a substituted or unsubstituted: arylene or divalent heterocyclic group; and Ar1 and Ar2 are each independently a substituted or unsubstituted: aryl or heterocyclic group.

Provided is an organic light emitting device including a light emitting layer comprising a compound of Chemical Formula 1 and a first organic material layer comprising a compound of Chemical Formula 2:

##STR00001## wherein: Cy1 to Cy5 are each independently one selected from among a substituted or unsubstituted: aromatic hydrocarbon ring, aliphatic hydrocarbon ring, and aromatic hetero ring, or a ring in which two or more rings selected from the above group are fused, one or more of Cy1 to Cy5 are a ring of Chemical Formula 1-A:

##STR00002## one to three of a* to d* are a position fused to or linked to Chemical Formula 1;

##STR00003## L1 to L3 are each independently a direct bond or a substituted or unsubstituted: arylene or divalent heterocyclic group; and Ar1 and Ar2 are each independently a substituted or unsubstituted: aryl or heterocyclic group.

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.

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 are an organic electric element comprising as a phosphorescent host material, a mixture of the compounds of Formula (1) and Formula (2), and an organic electronic device or apparatus thereof for achieving a high luminous efficiency, a low driving voltage, and an improved lifespan.