Compounds comprising phosphorescent metal complexes comprising cyclometallated ligands having a structure of

##STR00001##

In the vgs3, each of the E.sup.1 atoms is selected from C and N, except that E.sup.1g is selected from C, N, and S. The E.sup.1 atoms collectively comprise an 18 pi-electron system, provided that E.sup.1a and E.sup.1p are different. The R.sup.1 substituents are each, independently, H, hydrocarbyl, heteroatom substituted hydrocarbyl, cyano, fluoro, OR.sup.2a, SR.sup.2a, NR.sup.2aR.sup.2b, BR.sup.2aR.sup.2b, or SiR.sup.2aR.sup.2bR.sup.2c, where the R.sup.2 substituents are each, independently, hydrocarbyl or heteroatom substituted hydrocarbyl. Any of the R.sup.1 or R.sup.2 substituents can be linked to form a saturated or unsaturated, aromatic or non-aromatic ring, provided that the R.sup.1 substituents are not present when the corresponding one of E atoms is N or S. Organic light emitting diode devices comprising these compounds are also described.

Electronic or optoelectronic device comprising a first electrode, a second electro, and an active layer arranged between and in electrical connection with the first and the second electrode. The active layer comprises at least one dye compound, which comprises small-molecule organic solar cells.

Compounds comprising phosphorescent metal complexes comprising cyclometallated imidazo[1,2-f]phenanthridine and diimidazo[1,2-a:1,2-c]quinazoline ligands, or isoelectronic or benzannulated analogs thereof, are described. Organic light emitting diode devices comprising these compounds are also described.

An OLED containing an emissive dopant that is a heteroleptic complex having the formula Ir(L.sub.A-B).sub.2(L.sub.C-D) is disclosed. In the formula, L.sub.A-B is

##STR00001##

and L.sub.C-D can be selected from

##STR00002##

Methods of making novel organic compounds containing a twisted aryl group are provided. In particular, the compounds provided contain a 2-phenylpyridine ligand having a twisted aryl group on the pyridine portion of the ligand. The compounds may be used in organic light emitting devices, particularly as emitting dopants. Devices comprising the compounds containing twisted aryl may demonstrate improved color, efficiency, stability and manufacturing.

Disclosed are a method for preparing a series of carbazole derivatives and use thereof in organic light-emitting diodes. The structure of the material is as shown in Formula I. An organic electroluminescent device prepared by the material can have a significantly improved power efficiency and an external quantum efficiency for the device and an extended life for an orange light or red light device; moreover, the material has characteristics, for example, methods for the synthesis and purification of the material are simple and suitable for large-scale production, and is an ideal choice as a luminescent material for organic electroluminescent devices. The use of the organic electroluminescent diode material as a carrier transport material or as a luminescent material alone or as a host material in a light-emitting layer also falls within the scope of protection. ##STR00001##

An organic semiconductor element in which an organic semiconductor layer contains a compound of Formula (1) and/or a compound of Formula (2) or contains a polymer having a structure of any one of Formulae (9) and (10):

##STR00001## in which X.sup.1 represents a nitrogen atom or CR.sup.a, rings A to D each represent a specific aromatic ring or an aromatic heterocyclic ring; Y.sup.1 represents an oxygen atom, a sulfur atom, CR.sup.b.sub.2, or NR.sup.c; R.sup.a to R.sup.c each represent hydrogen atoms or substituents; R.sup.1 and R.sup.2 each represent a to specific substituent; n represents 1 or 2; and * represents a bonding site.

Disclosed is a benzazole derivative having a heteroaryl group, wherein the benzazole derivative having the heteroaryl group is represented by Chemical Formula 1. Also disclosed is an organic electroluminescence device including an organic layer containing the benzazole derivative having the heteroaryl group:

##STR00001##

wherein, each of Z1, X1, X2, X3, Ar1, Ar2, Ar3, m1, m2 and q is the same as defined in the specification.

A phosphorescent emitter or delayed fluorescent and phosphorescent emitters represented by Formula I or Formula II, where M is platinum or palladium. ##STR00001##

Compounds comprising phosphorescent metal complexes comprising cyclometallated imidazo[1,2-f]phenanthridine and diimidazo[1,2-a:1,2-c]quinazoline ligands, or isoelectronic or benzannulated analogs thereof, are described. Organic light emitting diode devices comprising these compounds are also described.