An electroluminescent device and a display device including the same. The electroluminescent device includes a first electrode and a second electrode facing each other; a light emitting layer disposed between the first electrode and the second electrode, the light emitting layer including a quantum dot; a hole transport layer disposed between the light emitting layer and the first electrode; and an electron transport layer disposed between the light emitting layer and the second electrode, wherein the hole transport layer, the light emitting layer, or a combination thereof includes thermally activated delayed fluorescence material, and the thermally activated delayed fluorescence material is present in an amount of greater than or equal to about 0.01 wt % and less than about 10 weight percent (wt %), based on 100 wt % of the hole transport layer, the light emitting layer, or the combination thereof including the thermally activated delayed fluorescence material.

A compound comprising a metal M and a first ligand L.sub.A having a structure of Formula I,

##STR00001##

is described. In Formula I, each independently represents a single bond or a double bond; each of X.sup.1′ to X.sup.4′ is independently C, N, or NR′; at least one of X.sup.1 to X.sup.4 is NR′; each R.sup.A′, R′, R.sup.1, R.sup.2, and R.sup.3 is independently hydrogen or a general substituent; at least one of R.sup.A′, R′, R.sup.1, R.sup.2, and R.sup.3 comprises the metal M; when X.sup.1 and X.sup.2 are both NR′, the B atom of Formula I forms a maximum of one direct bond to a nitrogen atom, and does not form a direct bond to an oxygen atom; and any two adjacent R.sup.A, R′, R.sup.1, R.sup.2, and R.sup.3 can be joined or fused to form a ring. Formulations, OLEDs, and consumer products including the compounds are also described.

An object of the present invention is to provide a novel electrochromic device (ECD). Disclosed is an electrochromic device (ECD) comprising two metal-complex-based electrochromic thin films individually acting as a working electrode and a counter electrode; (i) one of the two metal-complex-based electrochromic thin films being a film of a cathodically coloring metallo-supramolecular polymer comprising at least one organic ligand having a plurality of metal coordination positions and a metal ion of at least one transition metal and/or lanthanoid metal with the at least one organic ligand and the metal ion being arranged alternately, and the other of the two metal-complex-based electrochromic thin films being a film of an anodically coloring metal hexacyanoferrate (MHCF) represented by the formula: M(II).sub.3[Fe(III)CN.sub.6].sub.2 (where M=Fe, Ni or Zn), and (ii) the electrochromic device having a first conducting substrate; the film of the cathodically coloring metallo-supramolecular polymer; an electrolyte; the film of the anodically coloring metal hexacyanoferrate (MHCF); and a second conducting substrate being arranged in this order.

To provide an organic electroluminescent device having high efficiency while having a driving voltage. This organic electroluminescent device includes an anode, an organic layer and a cathode stacked on a substrate, at least one layer of the organic layer is a light-emitting layer containing a first host, a second host and a light-emitting dopant material, the first host is selected from a compound represented by the following general formula (1), and the second host is selected from a biscarbazole compound binding at a position other than the N-position, an indolocarbazole compound, or a carbazole compound in which a plurality of carbazole rings bind at the N-position. In the formula, a ring A is represented by formula (1b) or (1c), X represents NR, S, O, or CR.sub.2, and at least one Y represents N.

The present invention relates to compounds suitable for use in electronic devices, and to electronic devices, especially organic electroluminescent devices, comprising these compounds.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a π complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or ≥1; is the number of ligands K, where o can be 0 or ≥1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

Provided is a light-emitting element with high emission efficiency. The light-emitting element includes a first organic compound, a second organic compound, and a guest material. The LUMO level of the first organic compound is lower than that of the second organic compound, and the HOMO level of the first organic compound is lower than that of the second organic compound. The LUMO level of a guest material is higher than that of the first organic compound, and the HOMO level of the guest material is lower than that of the second organic compound. The guest material has a function of converting triplet excitation energy into light emission. The first organic compound and the second organic compound form an exciplex.

An organic light-emitting device including a first compound represented by Formula 1 and a second compound represented by one of Formulae 2A and 2B. ##STR00001##

A compound of Formula I,

##STR00001##

is provided. In Formula I, rings A, B, and D are independently 5- or 6-membered rings; Z.sup.1-Z.sup.3 and X.sup.1-X.sup.5 are independently C or N; each of K.sup.1 and K.sup.2 are a direct bond, O, and S; Y.sup.1 is BR, NR.sup.1, O, S, Se, or CRR′; represents a single bond or no bond; when present, L.sup.1, L.sup.2, L.sup.3, and L.sup.4 are each independently a direct bond or a linker; each substituent is hydrogen or a general substituent and can be joined together to form a ring. Formulations, OLEDs, and consumer products containing the same are also provided.

An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, an organic layer between the first electrode and the second electrode and including an emission layer, and at least one of a first layer and a second layer, wherein the first layer is positioned in a path where light generated in the emission layer is transmitted to the outside through the first electrode and the second layer is positioned in a path where the light generated in the emission layer is transmitted to the outside through the second electrode. The first layer and the second layer each include a compound having a certain formula and absorbing external ultraviolet rays to prevent or reduce the ultraviolet (UV) rays from transmitting therethrough.