A method for producing the growth of a semiconductor material, in particular of type II-VI, uses a melt of the semiconductor placed in a sealed bulb under vacuum or under controlled atmosphere, the bulb being subjected to a sufficient temperature gradient for first maintaining the melt in the liquid state, then causing its progressive crystallization from the surface towards the bottom. The method further comprises an element capable of floating on the surface of the melt, and equipped with a substantially central bore, intended for receiving a seed crystal for permitting the nucleation leading to the preparation of a seed crystal, and also supporting the seed crystal above the melt while maintaining it in contact with the melt in order to permit the continued crystallization from the seed crystal by lowering the temperature gradient.

A TiAl intermetallic compound single crystal material and a preparation method therefor are disclosed. The alloy composition of the material comprises Ti.sub.aAl.sub.bNb.sub.c(C, Si).sub.d, wherein 43≦b≦49, 2≦c≦10, a+b+c=100, and 0≦d≦1 (at. %).

A mould for casting a component in a directional solidification casting process having a preferred direction of grain growth (non-axial <001>) comprises a shell defining a cavity for receiving molten material. The cavity defines a three dimensional shape made up of a finished component geometry portion (42, 43, 44) and a sacrificial geometry portion (45) wherein the sacrificial geometry portion (45) includes a notch (48) which is shaped and positioned so as to, in use, contain high angle grain boundaries between dendritic growth in the preferred direction (non-axial <001>) and dendritic growth in a competing direction to the preferred direction (axial <001>) within the sacrificial geometry portion of a casting solidifying in the mould.

Buckling of a vitreous silica crucible 12 or inward fall of a sidewall 15 is effectively suppressed. The vitreous silica crucible 12 includes the cylindrical sidewall 15 having an upward-opening rim, a mortar-shaped bottom 16 including a curve, and a round portion 17 connecting the sidewall 15 and the bottom 16. In the vitreous silica crucible 12 the per-unit area thermal resistance in the thickness direction of the sidewall 15 is higher than that of the round portion 17.

A germanium single-crystal wafer comprises silicon with an atomic concentration of from 3×10.sup.14 atoms/cc to 10×10.sup.13 atoms/cc, boron with an atomic concentration of from 1×10.sup.16 atoms/cc to 10×10.sup.18 atoms/cc, and gallium with an atomic concentration of from 1×10.sup.16 atoms/cc to 10×10.sup.19 atoms/cc. Further provided are a method for preparing the germanium single-crystal wafer, a method for preparing a germanium single-crystal ingot, and the use of the germanium single-crystal wafer for increasing the open-circuit voltage of a solar cell. The germanium single-crystal wafer has an improved electrical property in that it has a smaller difference in resistivity and carrier concentration.

A method of fabricating at least one single-crystal alloy semiconductor structure. At least one seed, containing an alloying material, on a substrate for growth of at least one single-crystal alloy semiconductor structure is formed. At least one structural form, formed of a host material, on the substrate is crystallized to form the at least one single-crystal alloy semiconductor structure. The at least one structural form is heated such that the material of the at least one structural form has a liquid state. Also, the at least one structural form is cooled, such that the material of the at least one structural form nucleates at the least one seed and crystallizes as a single crystal to provide at least one single-crystal alloy semiconductor structure, with a growth front of the single crystal propagating in a main body of the respective structural form away from the respective seed.

Methods and devices for detecting incident radiation are provided. The methods and devices use high quality single-crystals of photoactive semiconductor compounds in combination with metal anodes and metal cathodes that provide for enhanced photodetector performance.

A directional solidification casting method includes fluidly coupling a feed line conduit with a source of molten metal and with a directional solidification mold at a gating. The mold has an interior chamber with a shape of an object to be cast using directional solidification in a growth direction. The feed line conduit is fluidly coupled with the gating in a downward direction oriented at an angle that is closer to the growth direction of the mold than to another direction that is perpendicular to the growth direction of the mold. The method also includes positioning a downstream portion of the feed line conduit below the gating, directing the molten metal into the mold via the feed line conduit, and casting the object in the mold using directional solidification.

A manufacturing method includes providing a material that includes a plurality of particles and a binder that is uncured. The method also includes forming a first article from the material including curing the binder to bind a collection of the particles together into the first article. Furthermore, the method includes encasing at least a portion of the first article with an outer member. The outer member defines an internal cavity that corresponds to the first article. Additionally, the method includes heating the outer member and the first article to melt the collection of particles into a molten mass within the internal cavity of the outer member. Moreover, the method includes solidifying the molten mass within the outer member to form a second article. The second article corresponds to at least a portion of the internal cavity of the outer member.

A method includes providing a collection of particulate material and forming a first article therefrom. Forming the first article includes forming an outer shell with an outer surface that defines an outer periphery of the first article; forming a relief area of the first article that supports the outer shell, including forming a relief void in the relief area; and collecting a collection of the particulate material within the outer shell during formation of the first article. Moreover, the method includes encasing the first article with an outer member. The outer member defines an internal cavity with an internal surface that corresponds to the outer surface of the outer shell. The method further includes heating, which deforms the first article selectively at the relief void.