Proposed are a layered compound having indium and phosphide, a nanosheet that may be prepared using the same, and an electrical device including the materials. Proposed is a layered compound represented by K.sub.1-xIn.sub.yP.sub.z (0≤x≤1.0, 0.75≤y≤1.25, 1.25≤z≤1.75).

Disclosed is an apparatus for preparing a large-size single crystal, which relates to the field of semiconductor material preparation, and more particularly, to an apparatus for preparing a large-size single crystal from a plurality of small-size single crystals by connecting them in solid states. The apparatus includes a hydrocooling furnace, a solid connection chamber hermetically disposed in the hydrocooling furnace, and combined fixtures provided in the solid connection chamber, wherein a plurality of crystal pieces are fixed by the combined fixtures, a top column or a stress block is used for pressing the crystal piece through the combined fixtures, a heating wire surrounding the solid connection chamber is provided in the hydrocooling furnace, a vacuum tube is communicated with the solid connection chamber, and a thermocouple is disposed close to the combined fixtures. The present disclosure is advantageous in that: 1, single crystal pieces with a small size can be connected and prepared into a single crystal with a larger size, 2, in the preparation process, the problems in the conventional single crystal growth process, such as twinning and polycrystallization, can be excluded from consideration, 3, the equipment is simple, and 4, preparation of single crystals with any size is possible theoretically.

Disclosed is an apparatus for preparing a large-size single crystal, which relates to the field of semiconductor material preparation, and more particularly, to an apparatus for preparing a large-size single crystal from a plurality of small-size single crystals by connecting them in solid states. The apparatus includes a hydrocooling furnace, a solid connection chamber hermetically disposed in the hydrocooling furnace, and combined fixtures provided in the solid connection chamber, wherein a plurality of crystal pieces are fixed by the combined fixtures, a top column or a stress block is used for pressing the crystal piece through the combined fixtures, a heating wire surrounding the solid connection chamber is provided in the hydrocooling furnace, a vacuum tube is communicated with the solid connection chamber, and a thermocouple is disposed close to the combined fixtures. The present disclosure is advantageous in that: 1, single crystal pieces with a small size can be connected and prepared into a single crystal with a larger size, 2, in the preparation process, the problems in the conventional single crystal growth process, such as twinning and polycrystallization, can be excluded from consideration, 3, the equipment is simple, and 4, preparation of single crystals with any size is possible theoretically.

Embodiments of this disclosure include apparatus, systems, and methods for fabricating monolayers. In one example, a method includes forming a multilayer film having a plurality of monolayers of a two-dimensional (2D) material on a growth substrate. The multilayer film has a first side proximate the growth substrate and a second side opposite the first side.

A composite substrate of the present disclosure is a composite substrate comprising a piezoelectric substrate and a sapphire substrate which are directly bonded, wherein the ratio of the number of oxygen atoms to the number of aluminum atoms in the bonding surface region including the bonding surface of the sapphire substrate bonded to the piezoelectric substrate is less than 1.5. The piezoelectric device of the present disclosure comprises the composite substrate. A method for manufacturing the composite substrate of the present disclosure comprises a step of preparing a piezoelectric substrate and a sapphire substrate, a step of heat-treating the sapphire substrate in a reducing atmosphere or in a vacuum, and a step of directly bonding the piezoelectric substrate to the sapphire substrate.

A method for method for manufacturing a rutile titanium dioxide layer according to the inventive concept includes forming a sacrificial layer on a substrate, and depositing a titanium dioxide (TiO.sub.2) material on the sacrificial layer. The sacrificial layer includes a metal oxide of a rutile phase. An amount of oxygen vacancy of the sacrificial layer after depositing the titanium dioxide material is greater than an amount of oxygen vacancy of the sacrificial layer before depositing the titanium dioxide material. The metal oxide includes a metal different from titanium (Ti).

This invention provides two variations of methods of separating a surface layer of the semiconductor crystal. In the second variation of the method, pulse laser emission is generated; a focused laser beam is directed onto the crystal in such a way that focus is placed in the layer separation plane perpendicular the axis of the beam, a laser beam is moved in such a way that focus is moved in the layer separation plane with forming the non-overlapping local regions with a disturbed topology of the crystal structure and with reduced interatomic bonds, wherein the local regions is distributed over the whole plane, an external action disturbing the reduced interatomic bonds is applied to the separable layer. The invention allows separating flat lateral surface layers from semiconductor crystals, and thin semiconductor washes from cylindrical semiconductor boules.

This invention provides two variations of methods of separating a surface layer of the semiconductor crystal. In the second variation of the method, pulse laser emission is generated; a focused laser beam is directed onto the crystal in such a way that focus is placed in the layer separation plane perpendicular the axis of the beam, a laser beam is moved in such a way that focus is moved in the layer separation plane with forming the non-overlapping local regions with a disturbed topology of the crystal structure and with reduced interatomic bonds, wherein the local regions is distributed over the whole plane, an external action disturbing the reduced interatomic bonds is applied to the separable layer. The invention allows separating flat lateral surface layers from semiconductor crystals, and thin semiconductor washes from cylindrical semiconductor boules.

The present invention includes: transferring a C-plane sapphire thin film 1t having an off-angle of 0.5-5° onto a handle substrate composed of a ceramic material having a coefficient of thermal expansion at 800 K that is greater than that of silicon and less than that of C-plane sapphire; performing high-temperature nitriding treatment on the GaN epitaxial growth substrate 11 and covering the surface of the C-plane sapphire thin film 1t with a surface treatment layer 11a made of AlN; having GaN grow epitaxially on the surface treatment layer 11a; ion-implanting a GaN film 13; pasting and bonding together the GaN film-side surface of the ion-implanted GaN film carrier and a support substrate 12; performing peeling at an ion implantation region 13.sub.ion in the GaN film 13 and transferring a GaN thin film 13a onto the support substrate 12; and obtaining a GaN laminate substrate 10.

The present invention includes: transferring a C-plane sapphire thin film 1t having an off-angle of 0.5-5° onto a handle substrate composed of a ceramic material having a coefficient of thermal expansion at 800 K that is greater than that of silicon and less than that of C-plane sapphire; performing high-temperature nitriding treatment on the GaN epitaxial growth substrate 11 and covering the surface of the C-plane sapphire thin film 1t with a surface treatment layer 11a made of AlN; having GaN grow epitaxially on the surface treatment layer 11a; ion-implanting a GaN film 13; pasting and bonding together the GaN film-side surface of the ion-implanted GaN film carrier and a support substrate 12; performing peeling at an ion implantation region 13.sub.ion in the GaN film 13 and transferring a GaN thin film 13a onto the support substrate 12; and obtaining a GaN laminate substrate 10.