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.

A light absorption material comprising: a compound having a perovskite crystal structure represented by ABX.sub.3 where the A site contains (NH.sub.2).sub.2CH.sup.+, the B site contains Pb.sup.2+, and the X site contains I.sup.−. A ratio of the number of atoms of I to the number of atoms of Pb measured by an X-ray photoelectron spectroscopy is 2.7 or less, or a ratio of the number of atoms of I to the number of atoms of Pb measured by a Rutherford backscattering spectroscopy is 2.9 or less.

Provided is a hybridized perovskite quantum dot material. The quantum dot material comprises a kernel and surface ligands. The kernel is formed by R.sub.1NH.sub.3AB.sub.3 or (R.sub.2NH.sub.3).sub.2AB.sub.4, where R.sub.1 is methyl group, R.sub.2 is an organic molecular group, A is at least one selected from Ge, Sn, Pb, Sb, Bi, Cu and Mn, B is at least one selected from Cl, Br and I, A and B form a coordination octahedral structure, and R.sub.1NH.sub.3 or R.sub.2NH.sub.3 is filled in gaps of the coordination octahedral structure. The surface ligand is an organic acid or organic amine. The quantum dot material has a high fluorescence quantum yield.

Various embodiments may provide a device for providing a first optical light of a first wavelength and a second optical light of a second wavelength. The device may include a halide perovskite structure including a first pattern and a second pattern different from the first pattern, so that the first pattern is configured to provide the first optical light of the first wavelength and the second pattern is configured to provide the second optical light of a second wavelength different from the first wavelength, upon a light incident on the first pattern and the second pattern. The halide perovskite structure may include a halide perovskite material.

Colloidal perovskite nanoplatelets can provide a material platform, with tunability extending from the deep UV, across the visible, into the near-IR. The high degree of spectral tunability can be achieved through variation of the cation, metal, and halide composition as well as nanoplatelet thickness.

The present invention relates to a method for obtaining an n-type doped metal chalcogenide quantum dot solid-state element with optical gain for low-threshold, band-edge amplified spontaneous emission (ASE), comprising: —forming a metal chalcogenide quantum dot solid-state element, and —carrying out an n-doping process on its metal chalcogenide quantum dots to at least partially bleach its band-edge absorption, which comprises: —a partial substitution of chalcogen atoms by halogen atoms, in the metal chalcogenide quantum dots, and/or —a partial aliovalent-cation substitution of bivalent metal cations by trivalent cations, in the metal chalcogenide quantum dots; and —providing a substance on the metal chalcogenide quantum dots, to avoid oxygen p-doping. The present invention also relates to the obtained n-type doped metal chalcogenide quantum dot solid-state element, a method for obtaining a light emitter with that n-type doped metal chalcogenide quantum dot solid-state element, and the obtained light emitter.

A perovskite ink is provided. The perovskite ink comprises a first polar solvent. The first polar solvent has a boiling point of 150° C. or more and a melting point of 30° C. or less. The perovskite ink further comprises a first light emitting perovskite material mixed in the first polar solvent at a concentration in the range of 0.01 wt. % to 10 wt. %.

Provided are a perovskite film and method for manufacturing the same, a perovskite electroluminescent device and method for manufacturing the same, and a display device, which belongs to the technical field of displaying. The perovskite film comprises a crystalline perovskite and a halogenated amine ligand grafted onto the crystalline perovskite. Since the perovskite film comprises the halogenated amine ligand, the surface of the perovskite film is smooth, and the surface coverage of the crystalline perovskite is high without significant void defects. Meanwhile, the perovskite film also has a high fluorescence quantum yield due to the halogenated amine ligand comprised in the perovskite film.

There is provided a method of preparing formamidinium lead halide perovskite quantum dots having a photoluminescence quantum yield higher than before. The disclosed method comprises steps of: preparing a lead halide solution by dissolving lead halide (II), oleic acid and oleylamine in a nonpolar solvent; preparing a formamidinium solution by dissolving formamidine acetate salt and oleic acid in a nonpolar solvent; mixing the formamidinium solution and the lead halide solution to form quantum dots; and centrifuging the mixed solution to obtain sediment; dispersing the sediment in a nonpolar solvent to prepare a crude quantum dot solution; mixing the crude quantum dot solution with methyl acetate; and centrifuging the crude quantum dot solution mixed with the methyl acetate to obtain sediment as purified quantum dots. The durable quantum dots are stably formed by injecting the lead halide solution into the formamidinium solution heated at 60° C.-90° C.

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.