A method for the preparation of a cohesive non-porous perovskite layer on a substrate (104) comprising: forming a thin film of a solution containing a perovskite material dissolved in a solvent onto the substrate to form a liquid film (104) of the solution on the substrate, applying a crystallisation agent (112) to a surface of the film to precipitate perovskite crystals from the 5 solution to form the cohesive non-porous perovskite layer (116) on the substrate.

A semiconductor device is provided. The semiconductor device includes a template layer disposed over a substrate and having a trench therein, a buffer structure disposed over a bottom surface of the trench and comprising a metal oxide, a single crystal semiconductor structure disposed within the trench and over the buffer structure and a gate structure disposed over a channel region of the single crystal semiconductor structure.

A crystal preparation apparatus (100) and a crystal preparation method (700). The crystal preparation apparatus (100) comprises: a growth cavity (110), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); and a heating assembly (120), used for heating the growth cavity (110). The crystal preparation method (700) comprises: placing a raw material in the growth cavity (110) (710), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); heating the growth cavity (110) by means of the heating assembly (120) so as to melt the raw material into a melt (720); bonding a seed crystal (180) to a seed crystal holder (150) (730); lowering the seed crystal holder (150) to which the seed crystal (180) is bonded, so that the seed crystal (180) is in contact with the melt; and preparing a crystal on the basis of the seed crystal (180) and the melt (750).

A p-type SiC single crystal having lower resistivity than the prior art is provided. This is achieved by a method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the surface, to grow a SiC single crystal, the method comprising: using as the SiC solution a SiC solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al; and contacting a (0001) face of the SiC seed crystal substrate with the SiC solution to grow a SiC single crystal from the (0001) face.

A semiconductor device is provided. The semiconductor device includes a template layer disposed over a substrate and having a trench therein, a buffer structure disposed over a bottom surface of the trench and comprising a metal oxide, a single crystal semiconductor structure disposed within the trench and over the buffer structure and a gate structure disposed over a channel region of the single crystal semiconductor structure.

A method of forming single crystal perovskite according to an exemplary embodiment of the present invention includes: forming a preliminary thin film by applying a perovskite precursor solution containing an additive on a substrate; exposing the preliminary thin film to a vacuum state by transferring the preliminary thin film to a vacuum chamber; and switching an internal pressure of the vacuum chamber to an atmospheric pressure, wherein the additive includes a substituted or unsubstituted C1 to C30 aliphatic ammonium salt, a substituted or unsubstituted C6 to C30 aromatic ammonium salt, a substituted or unsubstituted C1 to C30 aliphatic amine salt, a substituted or unsubstituted C6 to C30 aromatic amine salt, or a combination thereof.

A method of forming single crystal perovskite according to an exemplary embodiment of the present invention includes: forming a preliminary thin film by applying a perovskite precursor solution containing an additive on a substrate; exposing the preliminary thin film to a vacuum state by transferring the preliminary thin film to a vacuum chamber; and switching an internal pressure of the vacuum chamber to an atmospheric pressure, wherein the additive includes a substituted or unsubstituted C1 to C30 aliphatic ammonium salt, a substituted or unsubstituted C6 to C30 aromatic ammonium salt, a substituted or unsubstituted C1 to C30 aliphatic amine salt, a substituted or unsubstituted C6 to C30 aromatic amine salt, or a combination thereof.