A compound has a perovskite type crystal structure containing A which is a monovalent cation, B which is a metal ion, and X which is a halide ion as components. The perovskite type crystal structure has a unit cell volume of 0.2000 nm.sup.3 or more and 0.2150 nm.sup.3 or less, an ionic radius of B of 0.7 Å or more and 1.4 Å or less, and an ionic radius of X of 0.5 Å or more and 2.5 Å or less.

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.

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.

Photoactive materials comprising organic-inorganic hybrid halide perovskite compounds are provided. Photovoltaic cells and light-emitting devices incorporating the photoactive materials into their light-absorbing and light-emitting layers, respectively, are also provided. The halide perovskites have an amAMX.sub.3 perovskite crystal structure, wherein am is an alkyl diamine cation, an aromatic diamine cation, an aromatic azole cation, a cyclic alkyl diamine cation or a hydrazinediium cation; A is a monovalent alkylammonium cation or an alkali metal cation; X is a halide ion or a combination of halide ions; and M is an octahedrally coordinated bivalent metal atom.

Photoactive materials comprising organic-inorganic hybrid halide perovskite compounds are provided. Photovoltaic cells and light-emitting devices incorporating the photoactive materials into their light-absorbing and light-emitting layers, respectively, are also provided. The halide perovskites have an amAMX.sub.3 perovskite crystal structure, wherein am is an alkyl diamine cation, an aromatic diamine cation, an aromatic azole cation, a cyclic alkyl diamine cation or a hydrazinediium cation; A is a monovalent alkylammonium cation or an alkali metal cation; X is a halide ion or a combination of halide ions; and M is an octahedrally coordinated bivalent metal atom.

Disclosed is a building blocks method for low-cost fabrication of single crystal organometallic perovskite materials with pseudo crystallized hole transporting material layer. This method uses self-assembled molecular monolayers SAM as building blocks. This approach enables creation of defect-free perovskite crystals with desired morphology and crystallinity in a controlled way. Additionally, the crosslinked molecular layers SAM play a role of hole transporting materials HTM and encapsulation against diffusion of metal atoms and gas molecules, thus enhancing the stability of the perovskite materials. This method is cost effective and can be scaled up.

The present disclosure relates to a method that includes treating a liquid that includes a first precursor at a concentration C.sub.1, a second precursor at a concentration C.sub.2, a third precursor at a concentration C.sub.3, and an additive at a concentration C.sub.4, where the treating results in a perovskite, each of C.sub.1, C.sub.2, and C.sub.3 are between 0.001 M and 100 M, inclusively, and at least one of C.sub.4/C.sub.1 or C.sub.4/C.sub.2 equals a ratio greater than or equal to zero

The present disclosure relates to a method that includes treating a liquid that includes a first precursor at a concentration C.sub.1, a second precursor at a concentration C.sub.2, a third precursor at a concentration C.sub.3, and an additive at a concentration C.sub.4, where the treating results in a perovskite, each of C.sub.1, C.sub.2, and C.sub.3 are between 0.001 M and 100 M, inclusively, and at least one of C.sub.4/C.sub.1 or C.sub.4/C.sub.2 equals a ratio greater than or equal to zero