A method for preparing silicon substrate having average crystallite size greater than or equal to 20 μm, including at least the steps of: (i) providing polycrystalline silicon substrate of which average grain size is less than or equal to 10 μm; (ii) subjecting substrate to overall homogeneous plastic deformation, at temperature of at least 1000° C.; (iii) subjecting substrate to localized plastic deformation in plurality of areas of substrate, called external stress areas, spacing between two consecutive areas being at least 20 μm, local deformation of substrate being strictly greater than overall deformation carried out in step (ii); step (iii) being able to be carried out subsequent to or simultaneous to step (ii); and (iv) subjecting substrate obtained in step (iii) to recrystallization heat treatment in solid phase, at temperature strictly greater than temperature used in step (ii), in order to obtain desired substrate.

A method for preparing silicon substrate having average crystallite size greater than or equal to 20 μm, including at least the steps of: (i) providing polycrystalline silicon substrate of which average grain size is less than or equal to 10 μm; (ii) subjecting substrate to overall homogeneous plastic deformation, at temperature of at least 1000° C.; (iii) subjecting substrate to localized plastic deformation in plurality of areas of substrate, called external stress areas, spacing between two consecutive areas being at least 20 μm, local deformation of substrate being strictly greater than overall deformation carried out in step (ii); step (iii) being able to be carried out subsequent to or simultaneous to step (ii); and (iv) subjecting substrate obtained in step (iii) to recrystallization heat treatment in solid phase, at temperature strictly greater than temperature used in step (ii), in order to obtain desired substrate.

A method for manufacturing a composite structure comprising a thin layer made of monocrystalline silicon carbide arranged on a carrier substrate made of silicon carbide, the method comprising: a) a step of providing a donor substrate made of monocrystalline silicon carbide, b) a step of ion implantation of light species into the donor substrate, to form a buried brittle plane delimiting the thin layer between the buried brittle plane and a free surface of the donor substrate, c) a succession of n steps of forming crystalline carrier layers, with n greater than or equal to 2; the n crystalline carrier layers being positioned on the front face of the donor substrate successively one on the other, and forming the carrier substrate; each formation step comprising: direct liquid injection chemical vapor deposition, at a temperature below 900° C., to form a carrier layer, the carrier layer being formed by an at least partially amorphous SiC matrix, and having a thickness of less than or equal to 200 microns; a crystallization heat treatment of the carrier layer, at a temperature of less than or equal to 1000° C., to form a crystalline carrier layer; d) a step of separation along the buried brittle plane, to form, on the one hand, a composite structure comprising the thin layer on the carrier substrate and, on the other hand, the rest of the donor substrate.

A method of forming a crystalline silicon film includes forming a first amorphous silicon film on a substrate, forming a crystal nucleation film in which crystal nuclei of silicon are formed by performing a first annealing on the substrate having the first amorphous silicon film formed thereon, performing etching with an etching gas, forming a second amorphous silicon film on the crystal nuclei remaining after the etching, and forming a crystalline silicon film by performing a second annealing on the substrate after the forming of the second amorphous silicon film to grow the crystal nuclei.

Methods for forming a graphene film on a silicon carbide material are provided, along with the resulting coated materials. The method can include: heating the silicon carbide material to a growth temperature (e.g., about 1,000° C. to about 2,200° C.), and exposing the silicon carbide material to a growth atmosphere comprising a halogen species. The halogen species reacts with the silicon carbide material to remove silicon therefrom. The halogen species can comprise fluorine (e.g., SiF.sub.4, etc.), chlorine (e.g., SiCl.sub.4), or a mixture thereof.

Methods for forming a graphene film on a silicon carbide material are provided, along with the resulting coated materials. The method can include: heating the silicon carbide material to a growth temperature (e.g., about 1,000° C. to about 2,200° C.), and exposing the silicon carbide material to a growth atmosphere comprising a halogen species. The halogen species reacts with the silicon carbide material to remove silicon therefrom. The halogen species can comprise fluorine (e.g., SiF.sub.4, etc.), chlorine (e.g., SiCl.sub.4), or a mixture thereof.

Fabricating a crystalline metal-phosphide layer may include providing a crystalline base substrate and a step of forming a crystalline metal-source layer. The method may further include performing a chemical conversion reaction to convert the metal-source layer to the crystalline metal phosphide layer. One or more corresponding semiconductor structures can be also provided.

Fabricating a crystalline metal-phosphide layer may include providing a crystalline base substrate and a step of forming a crystalline metal-source layer. The method may further include performing a chemical conversion reaction to convert the metal-source layer to the crystalline metal phosphide layer. One or more corresponding semiconductor structures can be also provided.

A p-type thermoelectric material according to one aspect of the present invention is configured such that at least any one of a Mg site, a Si site, a Sn site and/or a Ge site in a compound composed of magnesium (Mg), silicon (Si), tin (Sn) and germanium (Ge) is substituted with any one or more elements selected from the group consisting of alkali metals of group 1A and gold (Au), silver (Ag), copper (Cu), zinc (Zn), calcium (Ca) and gallium (Ga) of group 1B.

A p-type thermoelectric material according to one aspect of the present invention is configured such that at least any one of a Mg site, a Si site, a Sn site and/or a Ge site in a compound composed of magnesium (Mg), silicon (Si), tin (Sn) and germanium (Ge) is substituted with any one or more elements selected from the group consisting of alkali metals of group 1A and gold (Au), silver (Ag), copper (Cu), zinc (Zn), calcium (Ca) and gallium (Ga) of group 1B.