The present invention includes novel heterocyclic materials for use as blue phosphorescent materials in OLED devices. The novel materials include two fused 5-membered aromatic or pseudoaromatic rings, which are bonded with 6 membered aromatic rings to serve as chelation ligands for a transition metal. The novel materials were determined computationally to have appropriate triplet energies for use as blue emitters and to possess sufficient chemical stability for use in devices.

An organic light-emitting device including: a first electrode; a second electrode facing the first electrode; a first emission unit and a second emission unit between the first electrode and the second electrode; and a first charge generation layer between the first emission unit and the second emission unit; wherein the first emission unit includes a first emission layer and a first inorganic buffer layer, and the second emission unit includes a second emission layer and a second inorganic buffer layer.

An organic light-emitting device including: a first electrode; a second electrode facing the first electrode; a first emission unit and a second emission unit between the first electrode and the second electrode; and a first charge generation layer between the first emission unit and the second emission unit; wherein the first emission unit includes a first emission layer and a first inorganic buffer layer, and the second emission unit includes a second emission layer and a second inorganic buffer layer.

An organometallic compound represented by Formula 1:
M(L.sub.1).sub.n1(L.sub.2).sub.n2  Formula 1
wherein, in Formula 1, M is a transition metal, L.sub.1 is a ligand represented by Formula 2A, L.sub.2 is a ligand represented by Formula 2B, n1 is 1 or 2, wherein, when n1 is 2, two groups L.sub.1 are identical to or different from each other, n2 is 1 or 2, wherein, when n2 is 2, two group L.sub.2 are identical to or different from each other, the sum of n1 and n2 is 2 or 3, and L.sub.1 and L.sub.2 are different from each other ##STR00001##
wherein X.sub.1, ring CY.sub.1, ring CY.sub.2, ring CY.sub.14, R.sub.1 to R.sub.3, R.sub.11 to R.sub.14, Z.sub.1 to Z.sub.3, a1, a2, a3, b1, and c1 are the same as described in the description, and * and *′ in Formulae 2A and 2B each indicate a binding site to M in Formula 1.

Provided are an electroluminescent material and a device thereof. The electroluminescent material is a metal complex having a ligand represented by Formula 1 and can be used as light-emitting materials in electroluminescent devices. These new metal complexes can effectively regulate and control the luminescence wavelength, reduce the drive voltage of electroluminescent devices, greatly improve the current efficiency, power efficiency and EQE of electroluminescent devices, prolong the device lifetime, and provide better device performance. Further provided are an electroluminescent device and a compound composition.

Provided are organometallic compounds of formula Os(L.sub.A).sub.x(L.sub.B).sub.y(L.sub.C).sub.z, where L.sub.A has a structure of Formula I with the two indicated dashed lines for coordination to Os:

##STR00001##

Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

A phosphorescent emitter compound having a first ligand L.sub.A having a Formula I,

##STR00001##

is disclosed. An OLED having the compound incorporated therein is also disclosed.

A compound of the formula ML.sub.AL.sub.B where ligand L.sub.A is of Formula I, and ligand L.sub.B is of Formula II below. ##STR00001## M is selected from Os(II) or Ru(II), and the compound ML.sub.AL.sub.B has a formal neutral charge; and rings A, B, C, D, E, and F are independently a 5-membered or 6-membered aromatic ring, and R.sup.A, R.sup.B, R.sup.C, R.sup.D, R.sup.E,and R.sup.F each independently represent mono to the maximum allowable substitution, or no substitution. L.sup.1, L.sup.2, L.sup.3, and L.sup.4 independently represent a single bond or an organic linking group; W.sup.1, W.sup.2, W.sup.3, and W.sup.4 are independently selected from carbon or nitrogen; Y.sup.1, Y.sup.2, Y.sup.3, and Y.sup.4 are independently selected from carbon or nitrogen; and Z.sup.1, Z.sup.2, and Z.sup.3 are independently selected from carbon or nitrogen, and at least one of Z.sup.1, Z.sup.2, and Z.sup.3 is nitrogen. An organic electroluminescent device that includes an anode, a cathode, and an organic layer comprising a compound of the formula ML.sub.AL.sub.B where ligand L.sub.A is of Formula I, and ligand L.sub.B is of Formula II above. A consumer product comprising an organic light-emitting device (OLED) above.

A compound of Formula I ##STR00001##
wherein M is a metal selected from Ir or Os;
rings A, B, C, D, E, and F are independently a 5-membered or 6-membered aromatic ring; Z.sup.1 to Z.sup.14 are independently selected from C or N; X is selected from a direct bond, or a linker with one to ten backbone member atoms; and Y is selected from a direct bond, a linker with one to ten backbone member atoms, or is absent to provide an open hexadentate ligand. An organic electroluminescent device (OLED) that includes an anode, a cathode, and an organic layer comprising a compound of the Formula I, and a consumer product comprising the OLED.

An organic light emitting device (OLED) that includes an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer comprising a light-emitting dopant within a host material, the host material including an optically active host compound; wherein one enantiomer of the optically active host compound is present in an enantiomeric excess (ee) of at least 75%. A consumer product that includes the OLED.