A method including depositing a lead halide precursor ink onto a substrate; drying the lead halide precursor ink to form a first thin film; annealing the first thin film; and forming a perovskite material layer, wherein forming the perovskite material layer includes: depositing a benzylammonium halide precursor ink onto the first thin film; drying the benzylammonium halide precursor ink; depositing a formamidinium halide precursor ink onto the benzylammonium halide precursor ink; drying the formamidinium halide precursor ink to form a second thin film; and annealing the second thin film.

A method including depositing a lead halide precursor ink onto a substrate; drying the lead halide precursor ink to form a first thin film; annealing the first thin film; and forming a perovskite material layer, wherein forming the perovskite material layer includes: depositing a benzylammonium halide precursor ink onto the first thin film; drying the benzylammonium halide precursor ink; depositing a formamidinium halide precursor ink onto the benzylammonium halide precursor ink; drying the formamidinium halide precursor ink to form a second thin film; and annealing the second thin film.

The present disclosure relates to a perovskite sheet that includes two outer layers, each including A′X′; and a first layer that includes BX.sub.2, where B is a first cation, A′ is a second cation, X is a first anion, X′ is a second anion, and the first BX.sub.2 layer is positioned between the two outer layers.

The present disclosure relates to a perovskite sheet that includes two outer layers, each including A′X′; and a first layer that includes BX.sub.2, where B is a first cation, A′ is a second cation, X is a first anion, X′ is a second anion, and the first BX.sub.2 layer is positioned between the two outer layers.

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.

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.

The disclosure discloses a method for recycling lead paste in a spent lead-acid battery, comprising: (1) pretreating lead paste in a spent lead-acid battery as a raw material under vacuum; mixing the pretreated lead paste with a chlorination reagent to obtain reactants; and heating the reactants under vacuum to carry out a chlorination volatilization reaction, so that lead element in the pretreated lead paste is combined with chlorine element in the chlorination reagent to form lead chloride, which is then volatilized, and after the reaction is completed, chlorination residue and a crude lead chloride product are obtained by condensation and crystallization after volatilization; (2) purifying the crude lead chloride product obtained in the step (1) under vacuum to obtain a refined lead chloride product. The disclosure improves the overall process flow of the recycling method as well as parameter conditions of the respective steps thereof, and can effectively solve the problem of serious pollution in lead paste recycling in the prior art.

The disclosure discloses a method for recycling lead paste in a spent lead-acid battery, comprising: (1) pretreating lead paste in a spent lead-acid battery as a raw material under vacuum; mixing the pretreated lead paste with a chlorination reagent to obtain reactants; and heating the reactants under vacuum to carry out a chlorination volatilization reaction, so that lead element in the pretreated lead paste is combined with chlorine element in the chlorination reagent to form lead chloride, which is then volatilized, and after the reaction is completed, chlorination residue and a crude lead chloride product are obtained by condensation and crystallization after volatilization; (2) purifying the crude lead chloride product obtained in the step (1) under vacuum to obtain a refined lead chloride product. The disclosure improves the overall process flow of the recycling method as well as parameter conditions of the respective steps thereof, and can effectively solve the problem of serious pollution in lead paste recycling in the prior art.

Provided are metal halide perovskite light emitting device and method of manufacturing the same. The metal halide perovskite light emitting device uses perovskite film having a multi-dimensional crystal structure derived from a proton transfer reaction as light emitting layer. Due to self-assembled shell of the perovskite film, ion movement is suppressed and surface defects are removed. Thereby, photoluminescence intensity, luminescence efficiency and lifetime are improved. By injecting a fluorine-based material and a basic material into the PEDOT:PSS conductive polymer used as the conventional hole injection layer, the acidity is controlled and the work function of the interface is improved. Furthermore, chemically stable graphene barrier layer protects the electrode vulnerable to acid, so that a high-efficiency light emitting device can be manufactured.

Provided are metal halide perovskite light emitting device and method of manufacturing the same. The metal halide perovskite light emitting device uses perovskite film having a multi-dimensional crystal structure derived from a proton transfer reaction as light emitting layer. Due to self-assembled shell of the perovskite film, ion movement is suppressed and surface defects are removed. Thereby, photoluminescence intensity, luminescence efficiency and lifetime are improved. By injecting a fluorine-based material and a basic material into the PEDOT:PSS conductive polymer used as the conventional hole injection layer, the acidity is controlled and the work function of the interface is improved. Furthermore, chemically stable graphene barrier layer protects the electrode vulnerable to acid, so that a high-efficiency light emitting device can be manufactured.