A heterocyclic compound, a composition including the heterocyclic compound, and an organic light-emitting device including the heterocyclic compound are disclosed. The heterocyclic compound is represented by Formula 1: ##STR00001##
wherein, X.sub.1, L.sub.1, a1, Ar.sub.1, R.sub.1 to R.sub.6, b3, b4, and b5 are described herein.

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; light-emitting units in the number of n between the first electrode and the second electrode; and a charge-generation unit(s) in the number of n−1 between the adjacent light-emitting units. The light-emitting units each include an emission layer, and at least one of the charge-generation unit(s) includes an n-type charge-generation layer, a p-type charge-generation layer, and an interlayer between the n-type charge-generation layer and the p-type charge-generation layer. The p-type charge-generation layer includes a first material and a second material, the first material includes a hole-transporting organic compound, an inorganic insulation compound, or any combination thereof, the second material includes at least one inorganic semiconductor compound, the interlayer comprises a third material, and the third material is selected from an organic compound, an inorganic semiconductor compound, and an inorganic insulation compound.

A mixture contains a first compound represented by a formula (10) and a second compound represented by a formula (20), and the first compound and the second compound have structures different from each other. In the formula (10) and the formula (20), L.sub.12 is a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms or the like; Ar.sub.12 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms; L.sub.11, L.sub.21, and L.sub.22 are each independently a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or the like; Ar.sub.11, Ar.sub.21, and Ar.sub.22 are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms; and R.sub.11 to R.sub.18 and R.sub.21 to R.sub.28 are each independently a hydrogen atom or a substituent.

##STR00001##

To provide a compound for further improving the capability of an organic EL device, an organic electroluminescent element having a further improved device capability, and an electronic device including the organic electroluminescent element. Disclosed are a compound represented by the following formula (1) or formula (2) (wherein each symbol in each formula is as defined in the description), an organic electroluminescent element containing the compound, and an electronic device including the organic electroluminescent element.

##STR00001##

Provided are organometallic compounds including a ligand L.sub.A of Formula I ##STR00001##

The present invention relates to certain fluorenes, to the use of the compounds in an electronic device, and to an electronic device comprising at least one of these compounds. The present invention furthermore relates to a process for the preparation of the compounds and to a formulation and composition comprising one or more of the compounds.

An organic electroluminescence device inducting a cathode, an anode, and an emitting layer disposed between the cathode and the anode, wherein the emitting layer includes a compound represented by the following formula (1) and one or more compounds selected from the group consisting of compounds represented by each of formulas (11), (21), (31), (41), (51), (61), (71) and (81). In the formula (1), at least one of R.sub.1 to R.sub.8 is a deuterium atom,

##STR00001##

The present disclosure relates to an organic compound. The structure of the organic compound consists of a structure represented by formula (I) and a structure represented by formula (II); the structure represented by formula (I) is fused with the structure represented by formula (II); and * represents a connection point, in formula (I), capable of being fused with formula (II). When being used to the organic light-emitting layer of an organic electroluminescent device, the organic compound of the present application can effectively improve the device efficiency of the device and prolong the service life of the organic electroluminescent device.

##STR00001##

A compound represented by the following formula (1) (L.sub.1 is a single bond or an unsubstituted arylene group having 6 to 50 ring carbon atoms, and Ar.sub.1 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms).

##STR00001##

Provided are a condensed cyclic compound having the following structure: ##STR00001##
wherein ring D.sub.1 and ring D.sub.2 are each independently a C.sub.6-C.sub.20 aromatic ring, and an organic light-emitting device including the same.