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.

Embodiments provide a heterocyclic compound, a light-emitting device that includes the heterocyclic compound, and an electronic apparatus that includes 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 at least one of the heterocyclic compound. The heterocyclic compound is represented by Formula 1, which is explained in the specification:

##STR00001##

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.

A compound of formula (11) to (13)

##STR00001##

wherein R.sub.1 to R.sub.4 are each independently D.sub.1 of a formula (1-1) etc. or D.sub.2 of a formula (2-1) etc.

##STR00002##

at least one of R.sub.1 to R.sub.4 being D.sub.1, and at least one of R.sub.1 to R.sub.4 being D.sub.2. In (1-1) and (2-1), X.sub.1 is O or S, R.sub.101 to R.sub.110 and R.sub.161 to R.sub.168 are each independently H, a substituent etc. In at least one D.sub.1, at least one of R.sub.101 to R.sub.110 is a group of a formula (110) or (120):

##STR00003##

Z.sub.1 is a C etc., a ring (B) is an aromatic hydrocarbon ring etc., Y.sub.12 to Y.sub.14 are each independently CR.sub.10A etc., Y.sub.21 to Y.sub.24 are each independently CR.sub.20A etc., Z.sub.2 is an aryl group etc., and * is a bonding position.

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 compound of Chemical Formula 1: ##STR00001## where A and B each independently is a substituted or unsubstituted aryl group, a substituted or unsubstituted monocyclic or dicyclic heteroaryl group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted benzonaphthofuran group, a substituted or unsubstituted dibenzothiophene group, a substituted or unsubstituted benzonaphthothiophene group, a substituted or unsubstituted phenoxazine group, a substituted or unsubstituted phenothiazine group, a substituted or unsubstituted phenanthroline group, a substituted or unsubstituted benzoquinoline group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted silyl group, or a substituted or unsubstituted phosphine oxide group, or one of the following substituents: ##STR00002## and an organic light emitting device including the same.

A compound for an organic optoelectronic device, an organic optoelectronic device including the same, and a display device, the compound being represented by Chemical Formula 1: ##STR00001##

Provided is an organic light-emitting device including: an anode; a cathode provided to face the anode; a light-emitting layer provided between the anode and the cathode; a first organic material layer provided between the anode and the light-emitting layer; and a second organic material layer provided between the cathode and the light emitting layer in which each organic material, from among organic materials included in the light-emitting layer and the organic material layers, the band gap energy (E.sub.bg) of each of the organic materials except for a dopant compound is 3 eV or more, the first organic material layer comprises one or more compounds each composed of centrally sp3 carbon, the second organic material layer includes one or more compounds each composed of centrally sp3 carbon, and the first organic material layer and the second organic material layer include three or more compounds each composed of centrally sp3 carbon.

Compounds of formula (1):

##STR00001##

wherein each symbol is as defined in the description, may provide an organic electroluminescence device having a further improved performance.