A light emitting device is provided. The device comprises a first electrode, a second electrode and at least two emissive layers. A first emissive layer of the at least two emissive layers is disposed over the first electrode. A second emissive layer of the at least two emissive layers is disposed over the first emissive layer. The first emissive layer is in contact with the second emissive layer. The second electrode is disposed over the second emissive layer. At least one emissive layer of the at least two emissive layers comprises a perovskite light emitting material. The device comprises at least one further emissive layer of the at least two emissive layers, wherein the at least one further emissive layer comprises a perovskite light emitting material, an organic light emitting material or a quantum dot light emitting material.

A light emitting device is provided. The device comprises a first electrode, a second electrode and at least two emissive layers. A first emissive layer of the at least two emissive layers is disposed over the first electrode. A second emissive layer of the at least two emissive layers is disposed over the first emissive layer. The first emissive layer is in contact with the second emissive layer. The second electrode is disposed over the second emissive layer. At least one emissive layer of the at least two emissive layers comprises a perovskite light emitting material. The device comprises at least one further emissive layer of the at least two emissive layers, wherein the at least one further emissive layer comprises a perovskite light emitting material, an organic light emitting material or a quantum dot light emitting material.

The present application discloses a method of preparing a luminescent nano-sheet. The method includes preparing a precursor emulsion solution containing a metal halide and RNH.sub.3X, and having a molar ratio of metal halide to RNH.sub.3X in a range of approximately 0.6 to approximately 0.8; demulsifying the precursor emulsion solution to obtain a perovskite quantum dots material and a demulsified solution; and forming the luminescent nano-sheet by allowing the perovskite quantum dots material self-assemble into the luminescent nano-sheet. X is a halide, R is selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, and heterocyclyl.

The present application discloses a method of preparing a luminescent nano-sheet. The method includes preparing a precursor emulsion solution containing a metal halide and RNH.sub.3X, and having a molar ratio of metal halide to RNH.sub.3X in a range of approximately 0.6 to approximately 0.8; demulsifying the precursor emulsion solution to obtain a perovskite quantum dots material and a demulsified solution; and forming the luminescent nano-sheet by allowing the perovskite quantum dots material self-assemble into the luminescent nano-sheet. X is a halide, R is selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, and heterocyclyl.

Provided herein are organic-inorganic hybrid-perovskites, including metal halide perovskites having a 1D crystal structure. The metal halide perovskites may be luminescent. The metal halide perovskites may include a dopant, including an emitter dopant. Methods of forming metal halide perovskites, and devices including the metal halide perovskites also are provided.

Provided herein are organic-inorganic hybrid-perovskites, including metal halide perovskites having a 1D crystal structure. The metal halide perovskites may be luminescent. The metal halide perovskites may include a dopant, including an emitter dopant. Methods of forming metal halide perovskites, and devices including the metal halide perovskites also are provided.

The present invention provides: a layered perovskite that has a high band gap energy and an excellent carrier transport capacity; a light absorption layer containing the layered perovskite; a light-absorption-layer-equipped substrate and a photoelectric conversion element that have the light absorption layer; and a solar cell having the photoelectric conversion element. In the layered perovskite according to present invention, the inter-surface distance of (002) planes calculated from an X-ray diffraction peak obtained by an out-of-plane method is 2.6 to 5.0 nm, and, in the X-ray diffraction peak, an intensity ratio ((111) plane/(002) plane) of an X-ray diffraction peak intensity at a (111) plane with respect to an X-ray diffraction peak intensity at the (002) plane is 0.03 or more.

The present invention provides: a layered perovskite that has a high band gap energy and an excellent carrier transport capacity; a light absorption layer containing the layered perovskite; a light-absorption-layer-equipped substrate and a photoelectric conversion element that have the light absorption layer; and a solar cell having the photoelectric conversion element. In the layered perovskite according to present invention, the inter-surface distance of (002) planes calculated from an X-ray diffraction peak obtained by an out-of-plane method is 2.6 to 5.0 nm, and, in the X-ray diffraction peak, an intensity ratio ((111) plane/(002) plane) of an X-ray diffraction peak intensity at a (111) plane with respect to an X-ray diffraction peak intensity at the (002) plane is 0.03 or more.

A method of performing a chelating reaction comprising contacting a divalent metal with a compound of Formula (I): or a salt thereof wherein: each of R.sup.1-R.sup.4 is independently selected from the group consisting of CH.sub.2COOR.sup.a and CH.sub.2C(═O)NHR.sup.a; each of R.sup.5-R.sup.12 is independently selected from the group consisting of H and -L-X; each Ra is independently selected from the group consisting of H and -L-X; each L is independently selected from the group consisting of absent and a linking group; and each X is a biological agent; and wherein the contacting occurs at a temperature below about 40° C. to form a chelated composition.

##STR00001##

A hydroximic acid-metal hydroxide coordination complex and preparation and application thereof are disclosed. The hydroximic acid-metal hydroxide coordination complex is formed by a coordination of hydroximic acid with divalent or higher valent metal ions under an alkaline condition. The hydroximic acid-metal hydroxide coordination complex has a strong selectivity and a strong collection ability for metal oxide minerals such as tungsten-containing minerals, ilmenite, rutile, cassiterite, and rare earth. The preparation method is simple and low in costs, and is beneficial to industrialized production.