Provided is a preparation method for an ultrahigh-conductivity multilayer single-crystal laminated copper material, where multiple layers of single-crystal copper foils are laminated together to form a laminate, and the laminate is pressurized and annealed as one piece by performing pressurizing and high-temperature annealing at the same time, or the laminate is pressed as one piece by means of direct hot rolling, thereby obtaining an ultrahigh-conductivity multi-layer single-crystal laminated copper material, whereby, according to the method, multiple layers of single-crystal copper foils are used as raw materials, an ultrahigh-conductivity multi-layer single-crystal laminated copper material is prepared by means of hot rolling or pressing and annealing, and the conductivity of the copper material is greater than or equal to 105% IACS.

Provided is a preparation method for an ultrahigh-conductivity multilayer single-crystal laminated copper material, where multiple layers of single-crystal copper foils are laminated together to form a laminate, and the laminate is pressurized and annealed as one piece by performing pressurizing and high-temperature annealing at the same time, or the laminate is pressed as one piece by means of direct hot rolling, thereby obtaining an ultrahigh-conductivity multi-layer single-crystal laminated copper material, whereby, according to the method, multiple layers of single-crystal copper foils are used as raw materials, an ultrahigh-conductivity multi-layer single-crystal laminated copper material is prepared by means of hot rolling or pressing and annealing, and the conductivity of the copper material is greater than or equal to 105% IACS.

An analysis method of crystal growth conditions includes a step of calculating an evaluation function on the basis of results obtained by measuring crystals grown under varied crystal growth conditions, a step of performing machine learning of the evaluation function, and a step of obtaining optimum crystal growth conditions from a result of the machine learning, wherein the evaluation function is based on a difference between crystal quality data of an ideal crystal and crystal quality data of the crystal having been grown.

A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.

A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.

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).

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).

Proposed are a layered Group III-V compound containing phosphorus, 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 represented by [Formula 1] M.sub.x-mA.sub.yP.sub.z (Where M is at least one of Group II 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).

Proposed are a layered Group III-V compound containing phosphorus, 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 represented by [Formula 1] M.sub.x-mA.sub.yP.sub.z (Where M is at least one of Group II 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).

A method for manufacturing epitaxial films with multiple stress states, comprising steps of: providing a first single crystal substrate, and forming a sacrificial layer and a first epitaxial film on the first single crystal substrate, wherein the first epitaxial film is made of a first material;

removing the sacrificial layer to separate the first epitaxial film from the first single crystal substrate; transferring the first epitaxial film to a second single crystal substrate, wherein the second single crystal substrate is made of a second material, a partial surface of the second single crystal substrate being overlapped by the first epitaxial film; applying epitaxies onto the first epitaxial film and the second single crystal substrate to form a second epitaxial film on the first epitaxial film and the second single crystal substrate.