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.

A solid ionic conducting material for use in an electrochemical device comprises an oxyhydroxide or hydrated oxide derived from of an oxide with a perovskite, Brownmillerite, layered oxide, and/or K.sub.4CdCl.sub.6 structure, the elemental composition of the initial oxide being selected to provide suitable conduction properties for the derived anhydrous or hydrated oxyhydroxide or hydrated oxide. A method of making such a solid ionic conducting material, including treatment with water, and an electrochemical device incorporating such a solid ionic conducting material (optionally as an electrolyte) are also disclosed.

Disclosed herein are doped perovskite oxides. The doped perovskite oxides may be used as a cathode material in an electrochemical cell to electrochemically generate ammonia from N.sub.2. The doped perovskite oxides may be combined with nitride compounds, for instance iron nitride, to further increase the efficiency of the ammonia production.

There is provided a method for preparation of oxide support-nanoparticle composites, in which metal nanoparticles decorate with uniform size and distribution on the surface of an oxide support, and thus, high performance oxide support-nanoparticle composites that can be applied in the fields of heterogeneous catalysis can be provided.

The present invention relates, in general terms, to piezoelectric thin films with an empirical formula (K.sub.1xNa.sub.x).sub.yNbO.sub.3, wherein 0≤x≤1 and 0.64≤y≤0.95. In particular, the piezoelectric thin film comprises at least two adjacent NbO.sub.2 planes in an antiphase boundary, the at least two adjacent NbO.sub.2 planes displaced from each other by about half a lattice length in either the (100), (010) or (100) crystallographic plane. The present invention also relates to methods of fabricating the piezoelectric thin films.

A ferroelectric perovskite composition, comprising a perovskite oxide ABO.sub.3, and a doping agent selected from perovskites of Ba(Ni,Nb)O.sub.3 and Ba(Ni,Nb)O.sub.3-δ. The ferroelectric perovskite composition may be represented by the formula: xBa(Ni,Nb)O.sub.3.(1-x)ABO.sub.3 or xBa(Ni,Nb)O.sub.3-δ.(1-x)ABO.sub.3. A method of producing the ferroelectric perovskite composition in thin film form is also provided.

Articles, such as components for high temperature turbomachinery components, include one or more coatings bearing certain perovskite compositions resistant to incursion by liquid calcium-magnesium-aluminum-silicon-oxide (CMAS) materials during service. The CMAS-reactive material includes a perovskite-structured oxide, which comprises a) a rare earth element, b) niobium, tantalum or a combination of tantalum and niobium, and c) oxygen. The CMAS-reactive material is present in an effective amount to react with a CMAS composition at an operating temperature, thereby forming a reaction product having one or both of melting temperature and viscosity greater than that of the CMAS composition.

The present disclosure relates to a composition that includes a material of at least one of a perovskite structure, a perovskite-like structure, and/or a perovskitoid structure, where the material includes an isotope of an element, the isotope has more neutrons than protons, and the isotope is incorporated into the perovskite structure, the perovskite-like structure, and/or the perovskitoid structure. In some embodiments of the present disclosure, the isotope may make up between greater than 0% and 100% of the element.

According to a novel fabrication method, a new composition of matter includes a large percentage (e.g., 75% or higher percentage) of primary nanoparticles in the new composition of matter. The novel fabrication method reduces the size of nanoparticle clusters in material of the new composition of matter, allows fabrication of specific nanoparticle cluster sizes, and allows fabrication of primary nanoparticles. This new composition of matter can include a high permittivity and high resistivity dielectric compound. This new composition of matter, according to certain examples, has high permittivity, high resistivity, and low leakage current. In certain examples, the new composition of matter constitutes a dielectric energy storage device that is a battery with very high energy density, high operating voltage per cell, and an extended battery life cycle.