Nanoscale metal halide perovskites are provided. The nanoscale metal halide perovskites may have a 2D structure, a quasi-2D structure, or a 3D structure. Methods also are provided for making the nanoscale metal halide perovskites. The color emitted by the nanoscale metal halide perovskites may be tuned.

Nanoscale metal halide perovskites are provided. The nanoscale metal halide perovskites may have a 2D structure, a quasi-2D structure, or a 3D structure. Methods also are provided for making the nanoscale metal halide perovskites. The color emitted by the nanoscale metal halide perovskites may be tuned.

In a first aspect, the present invention relates to a perovskite material comprising negatively charged layers alternated with and neutralized by positively charged layers; the negatively charged layers having a general formula selected from the list consisting of: L.sub.n−1M.sub.nX.sub.3n+1, L.sub.nM.sub.nX.sub.3n+2, and L.sub.n−1M′.sub.nX.sub.3n+3, and the positively charged layers comprising: one or more organic ammonium cations independently selected from monovalent cations Q and divalent cations Q′, or a polyvalent cationic conjugated organic polymer Z, wherein Q, Q′ and Z comprise each a π-conjugated system in which at least 8 and preferably at least 10 atoms participate, L is a monovalent cation, M.sub.n are n independently selected metal cations averaging a valence of two, M′.sub.n are n independently selected metal cations averaging a valence equal to 2+2/n, X is a monovalent anion, and n is larger than 1.

In a first aspect, the present invention relates to a perovskite material comprising negatively charged layers alternated with and neutralized by positively charged layers; the negatively charged layers having a general formula selected from the list consisting of: L.sub.n−1M.sub.nX.sub.3n+1, L.sub.nM.sub.nX.sub.3n+2, and L.sub.n−1M′.sub.nX.sub.3n+3, and the positively charged layers comprising: one or more organic ammonium cations independently selected from monovalent cations Q and divalent cations Q′, or a polyvalent cationic conjugated organic polymer Z, wherein Q, Q′ and Z comprise each a π-conjugated system in which at least 8 and preferably at least 10 atoms participate, L is a monovalent cation, M.sub.n are n independently selected metal cations averaging a valence of two, M′.sub.n are n independently selected metal cations averaging a valence equal to 2+2/n, X is a monovalent anion, and n is larger than 1.

The present invention provides a method for purifying an organic compound, by which an organic compound having a reduced lead content is obtained from an organic compound that contains a lead component as an impurity. In this method for purifying an organic compound, the organic compound that contains a lead component is irradiated with ultraviolet light, and the lead component is subsequently removed from the organic compound. The present invention also provides a method for producing an organic compound, said method comprising purification of the organic compound by means of the above-described method for purifying an organic compound.

The present invention relates to specific complexes comprising heavy metal ions having an atomic number of 23 or higher and 83 or lower (in particular Ag.sup.1+, Ba.sup.2+, Pb.sup.2+, Gd.sup.3+ and Bi.sup.3+) and one or more hematein ligand(s). In particular, the invention relates to the use of the complexes as ex vivo contrast agents for a computed tomography scanning of a biological sample. Moreover, the invention relates to specific ex vivo methods for investigating a biological sample by means of computed tomography scanning methods, wherein the method comprises staining the biological sample with a solution comprising one or more of the complex(es); or wherein the method comprises staining the biological sample with a staining solution comprising hematein, and separately contacting the biological sample with one or more staining solution(s) comprising one or more heavy metal ions having an atomic number of 23 or higher and 83 or lower (in particular Ag.sup.1+, Ba.sup.2+, Pb.sup.2+, Gd.sup.3+ and Bi.sup.3+).

The present invention relates to specific complexes comprising heavy metal ions having an atomic number of 23 or higher and 83 or lower (in particular Ag.sup.1+, Ba.sup.2+, Pb.sup.2+, Gd.sup.3+ and Bi.sup.3+) and one or more hematein ligand(s). In particular, the invention relates to the use of the complexes as ex vivo contrast agents for a computed tomography scanning of a biological sample. Moreover, the invention relates to specific ex vivo methods for investigating a biological sample by means of computed tomography scanning methods, wherein the method comprises staining the biological sample with a solution comprising one or more of the complex(es); or wherein the method comprises staining the biological sample with a staining solution comprising hematein, and separately contacting the biological sample with one or more staining solution(s) comprising one or more heavy metal ions having an atomic number of 23 or higher and 83 or lower (in particular Ag.sup.1+, Ba.sup.2+, Pb.sup.2+, Gd.sup.3+ and Bi.sup.3+).

The present invention relates to the field of luminescent crystals (LCs), and more specifically to Quantum Dots (QDs) of formula A.sup.1.sub.aM.sup.2.sub.bX.sub.c, wherein the substituents are as defined in the specification. The invention provides methods of manufacturing such luminescent crystals, particularly by dispersing suitable starting materials in the presence of a liquid and by the aid of milling balls; to compositions comprising luminescent crystals and to electronic devices, decorative coatings; and to components comprising luminescent crystals.

The present invention relates to the field of luminescent crystals (LCs), and more specifically to Quantum Dots (QDs) of formula A.sup.1.sub.aM.sup.2.sub.bX.sub.c, wherein the substituents are as defined in the specification. The invention provides methods of manufacturing such luminescent crystals, particularly by dispersing suitable starting materials in the presence of a liquid and by the aid of milling balls; to compositions comprising luminescent crystals and to electronic devices, decorative coatings; and to components comprising luminescent crystals.

A method for preparing three-dimensional perovskite nanopixels of a digital display is provided. The method includes steps of preparing precursor ink by mixing methylammonium halide and lead halide and adding them into another mixture, adding the precursor ink into a nanopipette, placing the nanopipette with the precursor ink above a silicon substrate and apart from the silicon substrate by a certain distance, configuring the nanopipette to come into contact with the Si substrate such that a portion of the precursor ink having an interface surface of a shape of a meniscus is formed between the nanopipette and the silicon substrate, performing rapid evaporation of the portion of the precursor ink to facilitate crystallization of perovskite, moving the nanopipette upwardly at a constant speed such that the crystallization of perovskite proceeds upwardly, and terminating the crystallization of perovskite to generate a freestanding nanopixel for emitting light.