An organic thin film includes an organic solid crystal material and has mutually orthogonal refractive indices, n.sub.x, n.sub.y, and n.sub.z each having a value at 589 nm of between approximately 1.5 and approximately 2.6, where n.sub.x≠n.sub.y≠n.sub.z. The organic thin film may be birefringent, and may be configured as a single layer thin film, or plural organic thin films may be stacked to form a multilayer that may be incorporated into an optical element, such as a reflective polarizer.

An organic thin film includes an organic solid crystal material and has mutually orthogonal refractive indices, n.sub.x, n.sub.y, and n.sub.z each having a value at 589 nm of between approximately 1.5 and approximately 2.6, where n.sub.x≠n.sub.y≠n.sub.z. The organic thin film may be birefringent, and may be configured as a single layer thin film, or plural organic thin films may be stacked to form a multilayer that may be incorporated into an optical element, such as a reflective polarizer.

The invention relates to a process for the preparation of a solid allulose material comprising crystalline allulose, the method comprising the steps of (a) providing in an evaporating crystallizer an aqueous mother liquor containing dissolved allulose; (b) maintaining, preferably until the end of crystallization, the aqueous mother liquor within the evaporating crystallizer at a crystallization temperature within the range of from 20 to 80° C.; (c) maintaining, preferably until the end of crystallization, the vapor phase above the aqueous mother liquor within the evaporating crystallizer at a crystallization pressure within the range of from 40 to 500 mbar; and (d) inducing crystallization of allulose from the aqueous mother liquor at the crystallization temperature and at the crystallization pressure in a supersaturated state thereby obtaining the solid allulose material as a precipitate and a supernatant.

A method for screening a target compound for polymorphic forms is provided. The method comprises providing a library of mixed-crystal seeds, each mixed-crystal seed consisting essentially of the target compound and at least one structural analog that is structurally analogous to the target compound; and for each mixed-crystal seed: introducing the mixed-crystal seed into a crystallization medium comprising the target compound, under conditions suitable for crystallization of the target compound; monitoring the formation of crystals of the target compound; and when formed, characterizing the crystals of the target compound.

A method for screening a target compound for polymorphic forms is provided. The method comprises providing a library of mixed-crystal seeds, each mixed-crystal seed consisting essentially of the target compound and at least one structural analog that is structurally analogous to the target compound; and for each mixed-crystal seed: introducing the mixed-crystal seed into a crystallization medium comprising the target compound, under conditions suitable for crystallization of the target compound; monitoring the formation of crystals of the target compound; and when formed, characterizing the crystals of the target compound.

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

An optical element includes an optical crystal and an antireflection film coating the surface of the optical crystal. The antireflection film contains an organic compound that includes, as a structural unit, at least one of a compound containing a cyclic structure to which a fluorine atom is bound and a compound containing a cyclic olefin structure.

An optical element includes an optical crystal and an antireflection film coating the surface of the optical crystal. The antireflection film contains an organic compound that includes, as a structural unit, at least one of a compound containing a cyclic structure to which a fluorine atom is bound and a compound containing a cyclic olefin structure.

Embodiments generally relate to methods for depositing silicon-phosphorous materials, and more specifically, relate to using silicon-phosphorous compounds in vapor deposition processes (e.g., epitaxy, CVD, or ALD) to deposit silicon-phosphorous materials. In one or more embodiments, a method for forming a silicon-phosphorous material on a substrate is provided and includes exposing the substrate to a deposition gas containing one or more silicon-phosphorous compounds during a deposition process and depositing a film containing the silicon-phosphorous material on the substrate. The silicon-phosphorous compound has the chemical formula [(R.sub.3-vH.sub.vSi)—(R.sub.2-wH.sub.wSi).sub.n].sub.xPH.sub.yR′.sub.z, where each instance of R and each instance of R′ are independently an alkyl or a halogen, n is 0, 1, or 2; v is 0, 1, 2, or 3; w is 0, 1, or 2; x is 1, 2, or 3; y is 0, 1, or 2; z is 0, 1, or 2, and where x+y+z=3.