A vapor phase epitaxy method of growing a III-V layer with a doping that changes from a first conductivity type to a second conductivity type on a surface of a substrate or a preceding layer in a reaction chamber from the vapor phase from an epitaxial gas flow comprising a carrier gas, at least one first precursor for an element from main group III, and at least one second precursor for an element from main group V, wherein when a first growth height is reached, a first initial doping level of the first conductivity type is set by means of a ratio of a first mass flow of the first precursor to a second mass flow of the second precursor, then the first initial doping level is reduced to a second initial doping level of the first or low second conductivity type.

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).

A method of forming crystalline sheets using a Horizontal Ribbon Growth process, where the sheet of material formed in the process is withdrawn from a crucible in a specified manner to reduce instabilities in the process and to regulate crystal growth dynamics.

A method of forming crystalline sheets using a Horizontal Ribbon Growth process, where the sheet of material formed in the process is withdrawn from a crucible in a specified manner to reduce instabilities in the process and to regulate crystal growth dynamics.

A method of performing heteroepitaxy comprises exposing a substrate to a carrier gas, a first precursor gas, a Group II/III element, and a second precursor gas, to form a heteroepitaxial growth of one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN on the substrate; wherein the substrate comprises one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN; wherein the carrier gas is H.sub.2, wherein the first precursor is HCl, the Group II/III element comprises at least one of Zn, Cd, Hg, Al, Ga, and In; and wherein the second precursor is one of AsH.sub.3 (arsine), PH.sub.3 (phosphine), H.sub.2Se (hydrogen selenide), H.sub.2Te (hydrogen telluride), SbH.sub.3 (hydrogen antimonide), H.sub.2S (hydrogen sulfide), and NH.sub.3 (ammonia). The process may be an HVPE (hydride vapor phase epitaxy) process.

A method of performing heteroepitaxy comprises exposing a substrate to a carrier gas, a first precursor gas, a Group II/III element, and a second precursor gas, to form a heteroepitaxial growth of one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN on the substrate; wherein the substrate comprises one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN; wherein the carrier gas is H.sub.2, wherein the first precursor is HCl, the Group II/III element comprises at least one of Zn, Cd, Hg, Al, Ga, and In; and wherein the second precursor is one of AsH.sub.3 (arsine), PH.sub.3 (phosphine), H.sub.2Se (hydrogen selenide), H.sub.2Te (hydrogen telluride), SbH.sub.3 (hydrogen antimonide), H.sub.2S (hydrogen sulfide), and NH.sub.3 (ammonia). The process may be an HVPE (hydride vapor phase epitaxy) process.

The present application discloses a gallium arsenide single crystal and preparation method thereof. The gallium arsenide single crystal has a carrier concentration of 1×10.sup.18-4×10.sup.18/cm.sup.3, and a migration rate of 1700-2600 cm.sup.2/v.Math.s; at a same carrier concentration, B atom density in the gallium arsenide single crystal obtained using Si.sub.xAs.sub.y compound as a dopant is at least 20% lower than that obtained using Si substance as a dopant; B content in the gallium arsenide single crystal is 5×10.sup.18/cm.sup.3 or lower. The preparation method for the gallium arsenide single crystal is that, before growth of the gallium arsenide single crystal, the Si.sub.xAs.sub.y compound is distributed into a gallium arsenide polycrystal.

The present application discloses a gallium arsenide single crystal and preparation method thereof. The gallium arsenide single crystal has a carrier concentration of 1×10.sup.18-4×10.sup.18/cm.sup.3, and a migration rate of 1700-2600 cm.sup.2/v.Math.s; at a same carrier concentration, B atom density in the gallium arsenide single crystal obtained using Si.sub.xAs.sub.y compound as a dopant is at least 20% lower than that obtained using Si substance as a dopant; B content in the gallium arsenide single crystal is 5×10.sup.18/cm.sup.3 or lower. The preparation method for the gallium arsenide single crystal is that, before growth of the gallium arsenide single crystal, the Si.sub.xAs.sub.y compound is distributed into a gallium arsenide polycrystal.

A multi-layer thin film composite is formed by applying a thin film formed from non-single-crystalline oxide onto a substrate; applying a protection film onto the thin film; and supplying energy to the thin film through at least one of the protection film or the substrate.