An aspect of the present disclosure is a method that includes combining a first organic salt (A.sup.1X.sup.1), a first metal salt) a second organic salt (A.sup.2X.sup.3), a second metal salt (M.sup.2Cl.sub.2), and a solvent to form a primary solution, where A.sup.1X.sup.1 and M.sup.1(X.sup.2).sub.2 are present in the primary solution at a first ratio between about 0.5 to 1.0 and about 1.5 to 1.0, and A.sup.2X.sup.3 to M.sup.2Cl.sub.2 are present in the primary solution at a second ratio between about 2.0 to 1.0 and about 4.0 to 1.0. In some embodiments of the present disclosure, at least one of A.sup.1 or A.sup.2 may include at least one of an alkyl ammonium, an alkyl diamine, cesium, and/or rubidium.

Embodiments of the present disclosure pertain to methods of forming a co-crystallized composition by mixing a first molecule in a solid phase with a second molecule in a liquid phase to form a mixture, and then co-crystallizing the mixture to form the co-crystallized composition in the form of a crystalline solid. The mixing of the first and second molecules may occur through the utilization of mechanical force, such as milling. The co-crystallization of the first and second molecules may occur by adding a solvent to the mixture of the molecules and then evaporating the added solvent. The methods may also include a step of utilizing the co-crystallized composition as seed crystals to grow additional co-crystallized compositions. Further embodiments of the present disclosure pertain to the formed co-crystallized compositions.

Organic-inorganic hybrid perovskite (OIHP) based photo-responsive devices include an OIHP active layer disposed between a cathode layer and an anode layer, and an electron extraction layer disposed between the cathode layer and the active layer. The electron extraction layer includes a layer of C.sub.60 directly disposed on the active layer. The active layer includes an organometal trihalide perovskite layer (e.g., CH.sub.3NH.sub.3PbI.sub.2X, where X includes at least one of Cl, Br, or I).

A system and method for patterned growth of halide perovskite nanocrystals is disclosed. This method allows control over the size, number and position of the nanocrystals, while ensuring compatibility with device integration processes. The method uses a topographical template comprising a plurality of wells with asymmetric surface wetting to confine the nanocrystal growth to within the wells. Further, the shape and surface wetting properties of the wells are used to induce local directional forces to guide nanocrystal positioning during the growth process. With this technique, scalable arrays of nanocrystals with tunable dimensions and precise positional accuracy are possible. As an example, this method allows arrays of active nanoscale perovskite light emitting diodes (LEDs).

A system and method for patterned growth of halide perovskite nanocrystals is disclosed. This method allows control over the size, number and position of the nanocrystals, while ensuring compatibility with device integration processes. The method uses a topographical template comprising a plurality of wells with asymmetric surface wetting to confine the nanocrystal growth to within the wells. Further, the shape and surface wetting properties of the wells are used to induce local directional forces to guide nanocrystal positioning during the growth process. With this technique, scalable arrays of nanocrystals with tunable dimensions and precise positional accuracy are possible. As an example, this method allows arrays of active nanoscale perovskite light emitting diodes (LEDs).

A method for the preparation of a cohesive non-porous perovskite layer on a substrate (104) comprising: forming a thin film of a solution containing a perovskite material dissolved in a solvent onto the substrate to form a liquid film (104) of the solution on the substrate, applying a crystallisation agent (112) to a surface of the film to precipitate perovskite crystals from the 5 solution to form the cohesive non-porous perovskite layer (116) on the substrate.

A method for the preparation of a cohesive non-porous perovskite layer on a substrate (104) comprising: forming a thin film of a solution containing a perovskite material dissolved in a solvent onto the substrate to form a liquid film (104) of the solution on the substrate, applying a crystallisation agent (112) to a surface of the film to precipitate perovskite crystals from the 5 solution to form the cohesive non-porous perovskite layer (116) on the substrate.

Method for preparing a crystal structure analysis sample for determining an absolute configuration of a chiral compound includes bringing a single crystal of a porous compound into contact with a solvent solution that contains a chiral compound, the single crystal of the porous compound including a three-dimensional framework, and either or both of pores and voids that are defined by the three-dimensional framework, and are three-dimensionally arranged in an ordered manner, the three-dimensional framework being formed by one molecular chain or two or more molecular chains, or formed by one molecular chain or two or more molecular chains, and a framework-forming compound, and comprising a chiral substituent of which the absolute configuration is known, the crystal structure analysis sample having a structure in which molecules of the chiral compound are arranged in either or both of the pores and the voids of the single crystal in an ordered manner.

Method for preparing a crystal structure analysis sample for determining an absolute configuration of a chiral compound includes bringing a single crystal of a porous compound into contact with a solvent solution that contains a chiral compound, the single crystal of the porous compound including a three-dimensional framework, and either or both of pores and voids that are defined by the three-dimensional framework, and are three-dimensionally arranged in an ordered manner, the three-dimensional framework being formed by one molecular chain or two or more molecular chains, or formed by one molecular chain or two or more molecular chains, and a framework-forming compound, and comprising a chiral substituent of which the absolute configuration is known, the crystal structure analysis sample having a structure in which molecules of the chiral compound are arranged in either or both of the pores and the voids of the single crystal in an ordered manner.

X-ray detectors are made by growing CsPbI.sub.3 on a treated surface of a conductive layer. Growth is controlled by increasing solvent concentration in the atmosphere in which the growth occurs. Columnar crystals grown in a plurality of wells extend between conductive surfaces at least one of which is pixelated to produce a columnar detector array.