Disclosed is a method of exchanging the anions of inorganic halide perovskite nanoparticles using cationic effect. More particularly, the method is a cation effect-based anion exchange method of being capable of improving optical stability while controlling the optical band energy of CsPbBr.sub.3 perovskite nanoparticles at room temperature. According to an embodiment of the present disclosure, a cation-anion pair suitable for anion exchange and stability improvement can be provided.

There is provided a protein-halide perovskite nanocrystal (p-HPNC) comprising: a crystalline core of halide perovskites and an outer layer made of protein surrounding the crystalline core. The protein has a net positive electric charge at a pH of 3 or less in its free state. The protein is linked to the surface of the crystalline core, and the halide perovskites have a formula ABX.sub.3, where A is a monovalent cation, B is a divalent cation, and X is a monovalent halide anion.

Inorganic perovskites doped with oxygen atoms or fluorine atoms, methods for making the doped perovskites, and hard radiation detectors incorporating the doped perovskites as photoactive layers are provided. The doped perovskites utilize lead oxide, lead fluoride, or compounds that thermally decompose into lead oxide or lead fluoride as dopant atom sources. During the crystallization of a perovskite in the presence of the dopant atom sources, oxygen or fluoride atoms from the dopant source are incorporated into the perovskite crystal lattice.

Bandgap-tunable perovskite compositions are provided having the formula CsPb(A.sub.xB.sub.y).sub.3, wherein A and B are each a halogen. The mixed halide perovskite composition has a morphology which suppresses phase segregation to stabilize a tuned bandgap of the mixed halide perovskite composition. For example, the perovskite may be in the form of nanocrystals embedded in a non-perovskite matrix, which, for example, may have the formula Cs.sub.4Pb(A.sub.xB.sub.y).sub.6, wherein A and B are each a halogen. Solar cells and light-emitting diodes comprising the mixed perovskite compositions are also provided.

This invention relates to a process for obtaining lead (Pb) and/or tin (Sn) from a lead- and/or tin-based material using a deep eutectic solvent.

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.

Core-shell particles may be based on red lead coated with pyrogenically produced titanium dioxide and/or a pyrogenically produced aluminum oxide, and a process may prepare such core-shell particles which may be used in lead-acid batteries. The red lead may include PbO.sub.2 in a range of from 25 to 32 wt. %.

The invention relates to sulfonated aminomethylated chelate resins, to a method for producing same, to the use thereof for obtaining and purifying metals, in particular rare earth metals, from aqueous solutions and organic liquids, and for producing highly pure silicon.

This disclosure provides systems, methods, and apparatus related to inorganic halide perovskite nanowires. In one aspect, a first solution comprising cesium oleate or rubidium oleate in a first organic solvent is provided. A second solution comprising a lead halide and a surfactant in a second organic solvent is provided. The halide is selected from a group consisting of chlorine, bromine, and iodine. The first solution and the second solution are mixed. A reaction between the cesium oleate or the rubidium oleate and the lead halide forms a plurality of nanowires comprising an inorganic lead halide perovskite.

A quantum dot luminescent material and a method of producing thereof. The quantum dot luminescent material includes a hole injection layer, a hole transport layer, a quantum dot light emitting layer, an electron transport layer, and an electron injection layer. The quantum dot luminescent layer is located on the hole transport layer, and the quantum dot luminescent layer includes uniformly distributed perovskite nanodots.