Provided are perovskite nanocrystalline particle and an optoelectronic device using the same. The perovskite nanocrystalline particle may include a perovskite nanocrystalline structure while being dispersible in an organic solvent. Accordingly, the perovskite nanocrystalline particle in accordance with the present invention has therein a perovskite nanocrystal having a crystalline structure in which FCC and BCC are combined; forms a lamellar structure in which an organic plane and an inorganic plane are alternately stacked; and can show high color purity since excitons are confined to the inorganic plane. In addition, the perovskite nanocrystalline particle have a particle size greater than or equal to a Bohr diameter beyond a quantum confinement effect, and simultaneously can implement high emission efficiency and emission wavelength which is almost not dependent on particle size. Furthermore, the perovskite nanocrystalline particle in accordance with the present invention, as a nanoparticle which is dispersible in an organic solvent, is applicable in various electronic devices such as light emitting devices, lasers, solar cells, etc.

Provided are: a light-emitting layer for a perovskite light-emitting device; a method for manufacturing the same; and a perovskite light-emitting device using the same. The method of the present invention for manufacturing a light-emitting layer for an organic and inorganic hybrid perovskite light-emitting device comprises a step of forming a first nanoparticle thin film by coating, on a member for coating a light-emitting layer, a solution comprising organic and inorganic perovskite nanoparticles including an organic and inorganic perovskite nanocrystalline structure. Thereby, a nanoparticle light emitter has therein an organic and inorganic hybrid perovskite having a crystalline structure in which FCC and BCC are combined; forms a lamella structure in which an organic plane and an inorganic plane are alternatively stacked; and can show high color purity since excitons are confined to the inorganic plane. In addition, it is possible to improve the luminescence efficiency and luminance of a device by making perovskite as nanoparticles and then introducing the same into a light-emitting layer.

Provided are a core-shell structured perovskite nanocrystalline particle light-emitting body, a method of preparing the same, and a light emitting device using the same. The core-shell structured organic-inorganic hybrid perovskite nanocrystalline particle light-emitting body or metal halide perovskite nanocrystalline particle light-emitting body is able to be dispersed in an organic solvent, and has a perovskite nanocrystal structure and a core-shell structured nanocrystalline particle structure. Therefore, in the perovskite nanocrystalline particle light-emitting body 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 an organic polymer.

Provided are an organic-inorganic hybrid perovskite nanocrystal particle light emitting body having a gradient structure, a method of producing the same, and a light emitting element using the same. The organic-inorganic hybrid perovskite nanocrystal particle light emitting body having a gradient structure includes an organic-inorganic hybrid perovskite nanocrystal which is dispersible in an organic solvent, wherein the nanocrystal has a gradient composition in which a composition is changed from the center thereof to the outside. Therefore, the gradual change in the content in the nanocrystal may be used to uniformly adjust a fraction in the nanocrystal, to reduce surface oxidation, and to improve exciton confinement in the perovskite present in large quantities inside the nanocrystal, and thus light emission efficiency may be improved and durability and stability may be increased.

Provided are a perovskite light emitting device containing an exciton buffer layer, and a method for manufacturing the same. The light emitting 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 light-emitting layer disposed on the exciton buffer layer and containing an organic-inorganic hybrid perovskite light emitting body; and a second electrode disposed on the light-emitting layer. Accordingly, an organic-inorganic hybrid perovskite is formed with a combined FCC and BSS crystal structure in a nanoparticle light-emitting body; the present invention forms a lamellar structure in which an organic plane and an inorganic plane are alternatively deposited; and an exciton is bound by the inorganic plane, thereby being capable of expressing high color purity.

Disclosed are a transition metal complex, a polymer, a mixture, a composition and the use thereof, wherein the transition metal complex has a structure of the general formula as shown in formula (1): ##STR00001##
The transition metal complex has a novel structure, and is an iridium (III) complex comprising rigid cycloalkyl groups. Since this type of auxiliary ligand increases the rigidity and symmetry of a molecule, the rigidity of a molecule is increased relative to a common ligand without the cycloalkyl groups, and as such, the whole complex has better chemical, optical, electrical and thermal stabilities. At the same time, since the modification occurs on the auxiliary ligand, the effect on the wavelength of the luminous maximum peak caused by a main ligand is relatively low, and therefore, a saturated luminous color may be retained. Therefore, the use of the transition metal complex according to the present invention in OLEDs, in particular as a doping material of a luminous layer, can provide a relatively high luminous efficiency and a relatively long lifetime of the device.

A condensed cyclic compound and an organic light-emitting device, the compound being represented by Formula 1 below: ##STR00001##

Provided are a wavelength converting particle, a method for manufacturing a wavelength converting particle, and a light-emitting diode containing a wavelength converting particle. The wavelength converting particle comprises a hybrid OIP nanocrystal that converts a wavelength of light generated by an excitation light source into a specified wavelength. Accordingly, it is possible to optically stabilize and improve color purity and light-emission performance without changes in a light-emitting wavelength range.

An organic light emitting device comprising a light emitting layer including a compound of Chemical Formula 1, and a first organic material layer including a compound of Chemical Formula 2.

##STR00001##

An ionic phosphorescent metal complex has a formula of formula (I). R.sub.1 and R.sub.2 are the same or different, and are independently selected from alkyl, aryl and heteroaryl, wherein the alkyl, aryl and heteroaryl are optionally substituted with 1-5 of the following groups: halogen, alkyl, alkoxy, alkylthio, amino, alkylamino, dialkylamino, arylamino, diarylamino, haloalkyl, cyano, nitro, alkenyl, aryl and heteroaryl optionally substituted with 1-3 aryl groups; R.sub.3 is independently selected from halogen, alkyl, haloalkyl, alkoxy, alkylthio, amino, alkylamino, dialkylamino, cyano, nitro or alkenyl; M is Cu(I), Ag(I) or Au(I). The organic light-emitting diode prepared by using the phosphorescent metal complex of formula (I) as a dopant for an emissive layer is capable of achieving high-performance organic electroluminescence and is applicable to the fields of lighting and flat-panel display.

##STR00001##