In a surface modification method for fluoride luminescent materials, an inorganic coating layer A.sub.xMF.sub.y coated substrate A.sub.xMF.sub.y:Mn.sup.4+ is mixed with an organic solution containing a metal phosphate, an alkoxysilane, an organic carboxylic acid or an organic amine. The solution is evaporated to give the organic-inorganic coating layer coated surface-modified fluoride luminescent material. The phosphor photoluminescence intensity and quantum efficiency of the modified phosphors can be maintained at 85%-95% under high temperature and high humidity conditions. After being coated with the inorganic coating layer, the surface defects of the phosphor are reduced, and the photoluminescence intensity and quantum yield of the phosphor are increased by 5%-15%. After being coated with the organic coating layer, the photoluminescence intensity of the phosphor is reduced <3%.

A fluoride fluorescent material includes a composition including K, Ge, Mn.sup.4+, and F and having a molar ratio of K of 2, a total molar ratio of Ge and Mn.sup.4+ of 1, a molar ratio of Mn.sup.4+ of more than 0 and less than 0.2, and a molar ratio of F of 6 in 1 mol of the composition, has a light emission spectrum having a first light emission peak in a range of 615 nm or more and less than 625 nm having a full width at half maximum of 6 nm or less, and a second light emission peak in a range of 625 nm or more and less than 635 nm, and has an internal quantum of 85% or more efficiency under excitation of light having a wavelength of 450 nm.

There is provided a photovoltaic device that comprises a photoactive region, the photoactive region comprising a perovskite material of general formula A.sub.1-xA′.sub.xBX.sub.3-yX′.sub.y, wherein A is a formamidinium cation (HC(NH).sub.2).sub.2.sup.+), A′ is a caesium cation (Cs.sup.+) B is at least one divalent inorganic cation, X is iodide and X is bromide, and x is greater than 0 and equal to or less than 0.4 and y is greater than 0 and less than or equal to 3. There is also provided a method of producing a photovoltaic device comprising a photoactive region comprising the perovskite material, and formulations for use in the formation of the perovskite material.

The present application discloses a composite light-emitting material, a production method thereof, and use thereof, wherein the composite light-emitting material has a perovskite nanomaterial and a matrix; the perovskite nanomaterial comprises γ-CsPbI.sub.3 and an addition element M; and the addition element M is selected from at least one of Li, Na, K, and Rb.

The present disclosure provides a quantum dot light-emitting device, a preparing method and a display device. The quantum dot light-emitting device includes an anode, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer and a cathode laminated one on another. The quantum dot light-emitting layer includes heterodimer quantum dots, the heterodimer quantum dots include first quantum dots carrying a positive charge and second quantum dots carrying a negative charge, and each first quantum dot and each second quantum dot have a same energy gap and different positions of conduction band and valence band.

The present invention provides a quantum dot of which a surface is passivated with a short chain ligand, and a method of passivating a surface of the quantum dot using a ligand exchange reaction.

Methods and devices for detecting incident radiation are provided. The methods and devices use high quality single-crystals of photoactive semiconductor compounds in combination with metal anodes and metal cathodes that provide for enhanced photodetector performance.

The present invention is a method for producing perovskite type quantum dots, wherein, using a plurality of precursor solutions each containing a different element, each of the plurality of precursor solutions is heated and sprayed as an aerosol of the precursor solution, and the plurality of aerosols are collided to cause a gas phase reaction, dropping in a solvent to synthesize core particles containing the different elements. This provides a method for producing quantum dots that enables control of the particle size and yields nanoparticles with a uniform particle size even in large-scale synthesis.

A light-emitting layer for a halide perovskite light-emitting device, a method for manufacturing the same and a perovskite light-emitting device using the same are disclosed. The light-emitting layer can be manufactured by forming a first nanoparticle thin film by coating, on a member, a solution comprising halide perovskite nanoparticles having a halide perovskite nanocrystalline structure. Thereby, a nanoparticle light emitter has therein a halide perovskite having a crystal structure in which FCC and BCC are combined; and can show high color purity. 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 light-emitting layer for a halide perovskite light-emitting device, a method for manufacturing the same and a perovskite light-emitting device using the same are disclosed. The light-emitting layer can be manufactured by forming a first nanoparticle thin film by coating, on a member, a solution comprising halide perovskite nanoparticles having a halide perovskite nanocrystalline structure. Thereby, a nanoparticle light emitter has therein a halide perovskite having a crystal structure in which FCC and BCC are combined; and can show high color purity. 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.