Provided are compounds capable of functioning as an emitter in an organic light emitting device at room temperature, and the compounds are at least 40% deuterated. Also provided are their uses in OLED related electronic devices.

An organometallic compound, represented by Formula 1:

M.sub.1(Ln.sub.1).sub.n1(Ln.sub.2).sub.n2  Formula 1

wherein, in Formula 1, M.sub.1 is a transition metal, Ln.sub.1 is a ligand represented by Formula 1A, Ln.sub.2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2:

##STR00001##

wherein, in Formulae 1A, 1B, CY.sub.1, CY.sub.2, CY.sub.4, X.sub.1, X.sub.2, Y.sub.1, R.sub.1, R.sub.2, R.sub.10, R.sub.20, R.sub.40, R.sub.31, R.sub.32, R.sub.33, R.sub.34, R.sub.40, b10, b20, and b40 are as provided herein, and wherein * and * each indicate a binding site to M.sub.1.

A light-emitting device including a first electrode, a hole transport region disposed on the first electrode, a first light-emitting layer disposed on the hole transport region and emitting light of a first wavelength, a second light-emitting layer disposed on the hole transport region and emitting light of a second wavelength different from the first wavelength, an electron transport region disposed on the first light-emitting layer and the second light-emitting layer, and a second electrode disposed on the electron transport region, wherein the second light-emitting layer includes a first sub light-emitting layer including a first host and a first dopant and emitting the light of the second wavelength, and a second sub light-emitting layer including a second host different from the first host and a second dopant and emitting the light of the second wavelength. Accordingly, a luminous efficiency and device lifetime of the light-emitting device may be improved.

Provided is an organometallic compound including a first ligand L.sub.A selected from

##STR00001## ##STR00002##

In ligand L.sub.A, each of Y.sup.1 to Y.sup.10 is carbon or nitrogen; moiety B is a monocyclic or polycyclic fused ring structure including 5-membered and/or 6-membered rings; any two R.sub.A and R.sub.B can be fused or joined to form a ring; X is selected from O, S, Se, or NR; each R.sub.A and R.sub.B is independently hydrogen or a substituent selected from the general substituent defined herein; at least one R, R.sub.A, or R.sub.B is deuterium or a linking group between L.sub.A and another ligand that includes a deuterium substituted aromatic ring; and L.sub.A is coordinated to a metal M, selected from Os, Pd, Pt, Ir, Cu, Ag, or Au; and the compound is capable of emitting light with a peak maximum wavelength (λ.sub.max)≥700 nm at room temperature.

An organic light-emitting device having low-driving voltage, improved efficiency, and long lifespan includes: a first electrode; a second electrode facing the first electrode; a first layer between the first electrode and the second electrode, the first layer including a first compound; a second layer between the first layer and the second electrode, the second layer including a second compound; and a third layer between the second layer and the second electrode, the third layer including a third compound; wherein the first compound does not include a nitrogen-containing heterocyclic group comprising *═N—*′ as a ring forming moiety, and wherein the first compound, the second compound, and the third compound each independently include at least one group selected from groups represented by Formulae A to C:

##STR00001##

A printing formulation, an electronic device comprising a function layer prepared from the printing formulation and a preparation method for obtaining a functional material thin film by utilizing the printing formulation. The printing formulation comprises at least one functional material and at least one inorganic ester solvent, and the inorganic ester solvent can be selected from alkyl borate or alkyl phosphate.

Metal complexes with cyclic ligands having Formula (I), ##STR00001##
are disclosed. Ligands with cyclic structure are believed to be beneficial to the rigidity and stability of the metal complexes, which is desirable for improving OLED device performance.

Provided are a compound represented by Formula 1, an organic electroluminescent element comprising a first electrode, a second electrode, and an organic material layer formed between the first electrode and the second electrode, and electroluminescent device thereof, and by comprising the compound represented by Formula 1 in the organic material layer, the driving voltage of the organic electroluminescent element can be lowered, and the luminous efficiency and life time of the organic electroluminescent element can be improved.

The present invention provides a luminescent film containing at least a phosphorescent compound and a fluorescent compound, wherein the convolution integral value J of the emission spectrum of the phosphorescent compound and the absorption spectrum of the fluorescent compound satisfies equation (1), the light emission from the fluorescent compound accounts for at least 90% of the emission spectrum of the luminescent film, and the absolute photoluminescence quantum efficiency (PLQE) of the luminescent film is represented by equation (2). Equation (1): J≥1.5×10.sup.14, Equation (2): PLQE (a film composed of a phosphorescent compound and a host compound)×0.9≤PLQE (a film containing a phosphorescent compound and a fluorescent compound) [The lowest triplet excited state of the host compound is higher than the lowest triplet excited state of the phosphorescent compound, and does not suppress the luminescent property of the phosphorescent compound.]

The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. The organic electroluminescent device with improved driving voltage and/or power efficiency can be provided by using the organic electroluminescent compound according to the present disclosure.