An organometallic compound represented by Formula 1:

##STR00001##

wherein M.sub.1 and M.sub.2 are each independently a Period 1 transition metal, a Period 2 transition metal, or a Period 3 transition metal in the periodic table of elements; and wherein L.sub.1, L.sub.2, a1, a2, Ar.sub.1, Ar.sub.2, R.sub.1 to R.sub.4, and LK in Formula 1 are as described in the present disclosure.

Disclosed herein are modified chromium-dpoed zinc gallate (ZGC) nanocubes, which are characterized in respectively having a concave surface that is modified with (3-aminopropyl)triethoxysilane (APTES). The modified ZGC nanocubes produce long lasting luminescence (LLL) that lasts for at least 1.5 hours under X-ray or UV excitation. Also disclosed herein are methods for the preparation of the modified ZGC nanocubes; and methods for imaging an area of interest (e.g., cancer) in a live subject using the modified ZGC nanocubes as an imaging agent.

Provided are a core-shell structured perovskite particle light-emitter, a method of preparing the same, and a light emitting device using the same. The core-shell structured perovskite particle light-emitter or metal halide perovskite particle light-emitter has a perovskite nanocrystal structure and a core-shell structured particle structure. Therefore, in the perovskite particle light-emitter of the present invention, as a shell is formed of a substance having a wider band gap than that of a core, excitons may be more dominantly confined in the core, and durability of the nanocrystal may be improved to prevent exposure of the core perovskite to the air using a perovskite or inorganic semiconductor, which is stable in the air, or a polymer.

An object of the present invention is to provide a luminescent particle having an emission maximum wavelength in a long wavelength range of 680 nm or longer and exhibiting a high quantum yield; and a compound having an emission maximum wavelength in a long wavelength range of 680 nm or longer and exhibiting a high quantum yield in the particles. According to the present invention, provided is a luminescent particle containing at least one kind of compound represented by Formula (1) (definitions of substituents in the formula are as set forth in the description) and a particle.

##STR00001##

A quantum dot composition includes a quantum dot, and a ligand bonded to a surface of the quantum dot, wherein the ligand includes a head portion bonded to the surface of the quantum dot, a connecting portion connected to the head portion and including a metal, and a tail portion coordinated to the metal of the connecting portion. The quantum dot composition according to the present embodiments is used to form an emission layer of a light emitting element, and may thus increase service life and luminous efficiency of the light emitting element including the emission layer formed using the quantum dot composition.

Provided are a perovskite optoelectronic device containing an exciton buffer layer, and a method for manufacturing the same. The optoelectronic device of the present invention comprises: an exciton buffer layer in which a first electrode, a conductive layer disposed on the first electrode and comprising a conductive material, and a surface buffer layer containing fluorine-based material having lower surface energy than the conductive material are sequentially deposited; a photoactive layer disposed on the exciton buffer layer and containing a perovskite photoactive layer; and a second electrode disposed on the photoactive layer. Accordingly, a perovskite is formed with a combined FCC and BSS crystal structure in a nanoparticle photoactive layer. The present invention can also form a lamellar or layered structure in which an organic plane and an inorganic plane are alternatively deposited; and an exciton can be bound by the inorganic plane, thereby being capable of expressing high color purity.

A composition which is useful for producing a light emitting device having excellent external quantum efficiency and a light emitting device containing the composition are described. The light emitting device contains an anode, a cathode, and an organic layer disposed between the anode and the cathode and contains a composition containing at least two compounds (A) selected from the group consisting of a compound represented by the formula (FH) and a polymer compound containing a constitutional unit having a group obtained by removing from a compound represented by the formula (FH) one or more hydrogen atoms, and a compound (B) having a condensed hetero ring skeleton (b) containing a boron atom and a nitrogen atom in the ring.

##STR00001##

An organometallic compound, represented by Formula 1:

M.sub.1(L.sub.n1).sub.n1(L.sub.n2).sub.n2  Formula 1

wherein, M.sub.1 is a transition metal, L.sub.n1 is a ligand represented by Formula 1A, L.sub.n2 is a ligand represented by Formula 1B, n1 is 0, 1, or 2, and n2 is 1, 2, or 3,

##STR00001## wherein * and *′ each indicate a binding site to Mt, and CY.sub.1, CY.sub.2, R.sub.1, R.sub.2, R.sub.10, R.sub.20, X.sub.1, X.sub.2, Y.sub.1 to Y.sub.8, L.sub.1, Ar.sub.1, b10, b20, a1, and k1 are each as described herein.

A novel class of gold(III) compounds containing cyclometalated tridentate ligand and one aryl auxiliary ligand, both coordinated to a gold(III) metal center. ##STR00001## (a) X is nitrogen or carbon; (b) Y and Z are independently nitrogen or carbon; (c) A is cyclic structure (derivative) of pyridine, quinoline, isoquinoline or phenyl group; (d) B and C are independently cyclic structures (derivatives) of pyridine, quinoline, isoquinoline or phenyl groups; (e) B and C can be identical or non-identical, with the proviso that both B and C are not 4-tert-butylbenzene; (f) R′ is a substituted carbon, nitrogen, oxygen or sulfur donor ligand attached to the gold atom; (g) n is zero, a positive integer or a negative integer. wherein R′ is selected from, but not limited to, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic aryl and substituted heterocyclic aryl, alkoxy, aryloxy, amide, thiolate, sulfonate, phosphide, fluoride, chloride, bromide, iodide, cyanate, thiocyanate or cyanide. Rings A, B and C are independently benzene or pyridine, or aryl (derivatives) or pyridyl, quinolyl, isoquinolyl (derivatives) with, but not limited to, one or more alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, OR, NR.sub.2, SR, C(O)R, C(O)OR, C(O)NR.sub.2, CN, CF.sub.3, NO.sub.2, SO.sub.2, SOR, SO.sub.3R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or heterocyclic group, wherein R is independently alkyl, alkenyl, alkynyl, alkyaryl, aryl, or cycloalkyl.

The invention provides a process for producing a passivated semiconductor, which process comprises treating a semiconductor with a passivating agent, wherein: the semiconductor comprises a crystalline compound comprising: (i) one or more first cations (A); (ii) one or more metal cations (M); and (iii) one or more anions (X); and the passivating agent comprises a compound comprising an oxygen-oxygen single bond. A composition and the use of a passivating agent are also provided.