One variation of a method includes: ingesting an air sample captured during an air capture period at a target location for collection of a first mixture including carbon dioxide and a first concentration of impurities; conveying the first mixture through a liquefaction unit to generate a second mixture including carbon dioxide and a second concentration of impurities less than the first concentration of impurities; in a methanation reactor, mixing the second mixture with hydrogen to generate a first hydrocarbon mixture comprising a third concentration of impurities comprising nitrogen, carbon dioxide, and hydrogen; conveying the first hydrocarbon mixture through a separation unit configured to remove impurities from the first hydrocarbon mixture to generate a second hydrocarbon a fourth concentration of impurities less than the third concentration of impurities; and depositing the second hydrocarbon mixture in a diamond reactor containing a set of diamond seeds to generate a first set of diamonds.

A crystal raw material loading device and a crystal growth device includes a plurality of bearing units which are arranged adjacent to each other horizontally in turn, and the multiple bearing units include a first bearing unit arranged at one end of a small plane far away from the seed crystal bearing device. Along the direction from one end of the small plane far away from the seed crystal to one end of the small plane close to the seed crystal, from the first bearing unit to the bearing unit on the side of the small plane close to the seed crystal, the height of the raw material that can be carried by each bearing unit is reduced in turn.

Silicon single crystals having an oxygen concentration of greater than 2×10.sup.17 at/cm.sup.3, a concentration of pinholes having a diameter of greater than 100 μm of less than 1.0×10.sup.−5 l/cm.sup.3, a carbon concentration of less than 5.5×10.sup.14 at/cm.sup.3, an iron concentration of less than 5.0×10.sup.9 at/cm.sup.3, a COP concentration of fewer than 1000 defects/cm.sup.3, a LPIT concentration of fewer than 1 defect/cm.sup.2 and a crystal diameter of greater than 200 mm, are produced by the Czochralski method employing a purge gas at specified pressures and flow rates.

A class of erbium-doped silicate crystals have a general chemical formula of (Er.sub.xYb.sub.yCe.sub.zA.sub.(1-x-y-z)).sub.3RM.sub.3Si.sub.2O.sub.14, in which the range of x is 0.002 to 0.02, y is 0.005 to 0.1, and z is 0 to 0.15; A is one, two or three elements selected from Ca, Sr, or Ba; R is one or two elements selected from Nb or Ta; M is one or two elements selected from Al or Ga. Using one of such crystals as a gain medium and a diode laser at 940 nm or 980 nm as a pumping source, a 1.5 μm continuous-wave solid-state laser with high output power and high efficiency, as well as a pulse solid-state laser with high energy and narrow width can be obtained.

A method of making a liquid dispersion for the manufacture of a photonic crystal. The method comprises dispersing monodispersed spheres in a liquid to form a liquid dispersion, and subjecting the liquid dispersion to an ultrasonic treatment. Ammonia solution may also be added to the liquid dispersion. The ultrasound treatment breaks up agglomerations of monodispersed spheres, and the resulting photonic crystal made using the dispersion is more highly ordered and hence of higher quality.

Methods for producing a single crystal silicon ingot are disclosed. The ingot is doped with boron using solid-phase boric acid as the source of boron. Boric acid may be used to counter-dope the ingot during ingot growth. Ingot puller apparatus that use a solid-phase dopant are also disclosed. The solid-phase dopant may be disposed in a receptacle that is moved closer to the surface of the melt or a vaporization unit may be used to produce a dopant gas from the solid-phase dopant.

Embodiments of the disclosure an apparatus for solvothermal crystal growth, comprising: a pressure vessel having a cylindrical shape and a vertical orientation; a cylindrical heater having an upper zone and a lower zone that can be independently controlled; at least one end heater; and an inward-facing surface of a baffle placed within 100 millimeters of a bottom end or top end surface of the growth chamber. The end heater is configured to enable: a variation in the temperature distribution along a first surface to be less than about 10° C., and a variation in the temperature distribution along a second surface to be less than about 20° C., during a crystal growth process. The first surface has a cylindrical shape and is positioned within the pressure vessel, and the second surface comprises an inner diameter of the growth chamber, and the temperature distribution along the second surface is created within an axial distance of at least 100 millimeters of an end of the growth chamber proximate to the first surface.

The present application discloses a gallium arsenide single crystal and preparation method thereof. The gallium arsenide single crystal has a carrier concentration of 1×10.sup.18-4×10.sup.18/cm.sup.3, and a migration rate of 1700-2600 cm.sup.2/v.Math.s; at a same carrier concentration, B atom density in the gallium arsenide single crystal obtained using Si.sub.xAs.sub.y compound as a dopant is at least 20% lower than that obtained using Si substance as a dopant; B content in the gallium arsenide single crystal is 5×10.sup.18/cm.sup.3 or lower. The preparation method for the gallium arsenide single crystal is that, before growth of the gallium arsenide single crystal, the Si.sub.xAs.sub.y compound is distributed into a gallium arsenide polycrystal.

Disclosed are a silicon carbide powder, a method of manufacturing a silicon carbide powder, and a silicon carbide wafer. More particularly, the silicon carbide powder includes carbon and silicon and in the silicon carbide powder, O1s/C1s of a surface measured by X-ray photoelectron spectroscopy is 0.28 or less.

A vapor phase epitaxial growth device comprises a reactor vessel and a wafer holder arranged within the reactor vessel. The wafer holder includes a wafer holding surface configured to hold a wafer with a wafer surface oriented substantially vertically downward. The device comprises a first material gas supply pipe configured to supply a first material gas and arranged below the wafer holding surface. The device comprises a second material gas supply pipe configured to supply a second material gas and arranged below the wafer holding surface. The device comprises a gas exhaust pipe configured to exhaust gases and arranged below the wafer holding surface. A distance between the gas exhaust pipe and an axis line passing through a center of the wafer holding surface is greater than distances between the axis line and each of the first material gas supply pipe and the second material gas supply pipe.