An organic thin film includes an organic crystalline phase, where the organic crystalline phase defines a surface having a surface roughness (R.sub.a) of less than approximately 10 micrometers over an area of at least approximately 1 cm.sup.2. The organic thin film may be manufactured from an organic precursor and a non-volatile medium material that is configured to mediate the surface roughness of the organic crystalline phase during crystal nucleation and growth. The thin film may be formed using a suitably shaped mold, for example, and the non-volatile medium material may be disposed between a layer of the organic precursor and the mold during processing.

Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm.sup.−2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm.sup.−2 or less, or 100 cm.sup.−2 or less, or 10 cm.sup.−2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.

Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm.sup.−2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm.sup.−2 or less, or 100 cm.sup.−2 or less, or 10 cm.sup.−2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.

In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within ±15° relative to a [−1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [−1100] direction, and where the first measurement region is irradiated with an X ray in a direction within ±6° relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.

Proposed are a layered Group III-V arsenic compound, a Group III-V nanosheet that may be prepared using the same, and an electrical device including the materials. There is proposed a layered compound having a composition represented by [Formula 1] Mx-mAyAsz (Where M is at least one of Group I elements, A is at least one of Group III elements, x, y, and z are positive numbers which are determined according to stoichiometric ratios to ensure charge balance when m is 0, and 0<m<x).

Embodiments described herein relate generally to the large scale production of functionalized graphene. In some embodiments, a method for producing functionalized graphene includes combining a crystalline graphite with a first electrolyte solution that includes at least one of a metal hydroxide salt, an oxidizer, and a surfactant. The crystalline graphite is then milled in the presence of the first electrolyte solution for a first time period to produce a thinned intermediate material. The thinned intermediate material is combined with a second electrolyte solution that includes a strong oxidizer and at least one of a metal hydroxide salt, a weak oxidizer, and a surfactant. The thinned intermediate material is then milled in the presence of the second electrolyte solution for a second time period to produce functionalized graphene.

Embodiments described herein relate generally to the large scale production of functionalized graphene. In some embodiments, a method for producing functionalized graphene includes combining a crystalline graphite with a first electrolyte solution that includes at least one of a metal hydroxide salt, an oxidizer, and a surfactant. The crystalline graphite is then milled in the presence of the first electrolyte solution for a first time period to produce a thinned intermediate material. The thinned intermediate material is combined with a second electrolyte solution that includes a strong oxidizer and at least one of a metal hydroxide salt, a weak oxidizer, and a surfactant. The thinned intermediate material is then milled in the presence of the second electrolyte solution for a second time period to produce functionalized graphene.

A method for preparing a large-size two-dimensional layered metal thiophosphate crystal includes the following steps: 1) weighing raw materials of indium spheres, phosphorous lumps and sulfur granules according to a predetermined amount and proportion, mixing them, and using iodine as a transport agent and potassium iodide as a molten salt; 2) adding the raw materials, the iodine and the potassium iodide to a reaction vessel together, and vacuum sealing it under a certain pressure, and then subjecting it to a high-temperature reaction; 3) taking out the products after the reaction, and washing the products to remove the residual iodine and potassium iodide and obtain large-size two-dimensional layered metal thiophosphate crystals. This method is simple and highly efficient.

A method for preparing a large-size two-dimensional layered metal thiophosphate crystal includes the following steps: 1) weighing raw materials of indium spheres, phosphorous lumps and sulfur granules according to a predetermined amount and proportion, mixing them, and using iodine as a transport agent and potassium iodide as a molten salt; 2) adding the raw materials, the iodine and the potassium iodide to a reaction vessel together, and vacuum sealing it under a certain pressure, and then subjecting it to a high-temperature reaction; 3) taking out the products after the reaction, and washing the products to remove the residual iodine and potassium iodide and obtain large-size two-dimensional layered metal thiophosphate crystals. This method is simple and highly efficient.

A ribbon is formed such that the ribbon floats on a melt using a cold initializer facing an exposed surface of the melt. The ribbon is single crystal silicon. The ribbon is pulled from the silicon melt at a low angle off the melt surface. The ribbon is formed at a same rate as the pulling. The ribbon is separated from the melt at a wall of the crucible where a stable meniscus forms. The ribbon has a thickness between a first surface and an opposite second surface from 50 μm to 5 mm. The ribbon includes a first region extending a first depth from the first surface. The first region has a reduced oxygen concentration relative to a bulk of the ribbon.