A perovskite compound represented by Formula 1, a thin layer including the perovskite compound, and an optoelectronic device including the perovskite compound:

[A][B.sup.1.sub.nB.sup.2.sub.(1-n)][X].sub.3.  Formula 1

In Formula 1, A may be at least one selected from a monovalent organic cation, monovalent inorganic cation, and combinations thereof; B.sup.1 may be a thulium (II) (Tm.sup.2+) ion; B.sup.2 may be at least one divalent inorganic cation, where B.sup.2 is free of (e.g., does not include) Tm.sup.2+; n may be a real number that satisfies 0<n≦1; and X may be at least one monovalent anion.

The present disclosure is directed to new photoluminescent metal-organic frameworks (MOFs). The newly developed MOFs include either non rare earth element (REE) transition metal atoms or limited concentrations of REE atoms, including: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Ru, Ag, Cd, Sn, Sb, Ir, Pb, Bi, that are located in the MOF framework in site isolated locations, and have emission colors ranging from white to red, depending on the metal concentration levels and/or choice of ligand.

An organic electroluminescence device comprising an electron-transporting zone comprising

i) at least one compound represented by formula (I), and

ii) at least one rare earth metal, rare earth metal compound, and/or rare earth metal complex, wherein the electron-transporting zone does not comprise an alkali metal, an alkali metal compound, an alkali metal complex, an alkaline earth metal, an alkaline earth metal compound, and an alkaline earth metal complex; a material for an organic electroluminescence device comprising a combination of at least one compound of formula (I) and at least one rare earth metal, rare earth metal compound, and/or rare earth metal complex; an organic electroluminescence device comprising said organic electroluminescence device and the use of a compound of formula (I) in combination with at least one rare earth metal, rare earth metal compound, and/or rare earth metal complex, in an electron-transporting zone of an organic electroluminescence device, wherein the electron-transporting zone does not comprise an alkali metal, an alkali metal compound, an alkali metal complex, an alkaline earth metal, an alkaline earth metal compound, and an alkaline earth metal complex.

##STR00001##

A polyimide luminescent material, a preparation method, and a used thereof are disclosed; the polyimide luminescent material includes a polyimide resin and a rare earth complex distributed in the polyimide resin, wherein the polyimide resin is a condensation polymer of an aromatic diamine containing a bidentate chelate ligand and an aromatic dianhydride, and the rare earth complex and the bidentate chelate ligand are connected by a chemical bond. The luminescent material has enhanced fluorescence intensity, thermal stability, and mechanical properties. The preparation method is simple and easy, and is suitable for industrial production.

A light emitting device having an anode, a cathode, a first layer disposed between the anode and the cathode, and a second layer disposed between the anode and the first layer is provided. The second layer is a layer containing a crosslinked product of a polymer compound having a crosslinkable group. At least one of the first layer and the second layer contains a compound represented by the formula (T-1):

##STR00001##

Provided is a method of purifying a phosphorescent dopant, the method including reacting the phosphorescent dopant with Ag.sub.2O.

Visibly transparent photovoltaic devices are disclosed, such as those are transparent to visible light but absorb near-infrared light and/or ultraviolet light. The photovoltaic devices make use of transparent electrodes and near-infrared absorbing visibly transparent photoactive compounds, optical materials, and/or buffer materials.

The present invention relates to a composition of a superfluorescent cerium (III)-containing chelate having ultra-short decay time, especially a molecular composition for OLED applications, having a neutral donor in the form of a Ce(III) chelate and a neutral fluorescent receptor molecule. The composition of the present invention can be used to produce pure color luminescence with very short emission decay time, especially for a dark blue luminous region. The composition utilizes an excited state dual capture mechanism, and such kind of novel exciton capture mechanism can be classified into a fifth-generation organic light-emitting diode (OLED) and other photoelectric devices.

A metal-organic coordination compound, wherein the coordination compound comprises at least one divalent lanthanide coordinated by a cyclic organic ligand according to formula 1:

##STR00001## wherein i is larger than 3; and n is equal to 1, 2, or 3; and L for each occurrence is independently selected from divalent cyclic organic groups that can be substituted and that are formed by removing two hydrogen atoms from an organic cyclic molecule that can be substituted, arylenes, preferably 5- or 6-membered ring aromatic or heteroaromatic group, or biradical fragments of

##STR00002##

and X is independently selected for each occurrence from the group of:

##STR00003## wherein R.sub.1 and R.sub.2 are hydrogen or any covalently bound substituents being identical or different in each occurrence; and wherein R.sub.1 and/or R.sub.2 are at least in 3 occurrences not hydrogen, and wherein two groups R.sub.2 can be covalently linked with each other, thereby forming a further cyclic element, it also being possible that two cyclic organic ligands of formula 1 are covalently linked with each other by one or two divalent linking groups which divalent linking groups are formed of one R.sub.1 of each of the two cyclic organic ligands of formula 1 that are covalently linked with each other.

Provided is an OLED structure includes an organic layer having a primary phosphorescent emitter and a first host; where one of the following conditions is true: (1) the organic layer further includes a secondary emitter; or (2) the OLED further includes a second organic layer where the second organic layer includes a secondary emitter. The primary phosphorescent emitter has a peak emission wavelength λmax that is ≥600 nm and ≤750 nm; the secondary emitter has a peak emission wavelength λmax that is ≥750 nm; the primary phosphorescent emitter is capable of transferring energy to the secondary emitter; the first host has a lowest excited state triplet energy T1 that is at least 0.1 eV higher than that of the primary phosphorescent emitter; the primary phosphorescent emitter has the formula Pt(L.sup.1).sub.m; L.sup.1 can represent one or more ligands that are the same or different; each L.sup.1 is independently monodentate or multidentate; and m represents a maximum possible number of ligands L.sup.1 that can coordinate to Pt.