The techniques described herein relate to semiconductor structures, in some cases including epitaxial oxide heterostructures. An epitaxial oxide heterostructure can include a substrate, a first epitaxial oxide layer, and a second epitaxial oxide layer. The first epitaxial oxide layer can include a first epitaxial oxide material, where the first epitaxial oxide material includes: at least one of magnesium, nickel, and zinc; at least one of aluminum and gallium; and oxygen. The second epitaxial oxide layer can include a second epitaxial oxide material, where the second epitaxial oxide material includes: at least one of magnesium, nickel, and zinc; at least one of aluminum and gallium; and oxygen. The first epitaxial oxide material can have a first composition that is different from a second composition of the second epitaxial oxide material.

Sol-gel methods, apparatus and compositions for cladding optical fiber cores provide optical fibers, including single crystal optical fiber cores with polycrystalline cladding, having improved performance in a variety of applications, such as fiber lasers.

A method of forming a metal gallate spinel structure that includes mixing a divalent metal-containing salt and a gallium-containing salt in solution with fermentative or thermophilic bacteria. In the process, the bacteria nucleate metal gallate spinel nano-objects from the divalent metal-containing salt and the gallium-containing salt without requiring reduction of a metal in the solution. The metal gallate spinel structures, as well as light-emitting structures in which they are incorporated, are also described.

A method of forming a metal gallate spinel structure that includes mixing a divalent metal-containing salt and a gallium-containing salt in solution with fermentative or thermophilic bacteria. In the process, the bacteria nucleate metal gallate spinel nano-objects from the divalent metal-containing salt and the gallium-containing salt without requiring reduction of a metal in the solution. The metal gallate spinel structures, as well as light-emitting structures in which they are incorporated, are also described.

A high-throughput method for identifying single crystal hexagonal-SiC off-axis surfaces that support surface chemistries and kinetics to selectively produce various epitaxial growth modes of the metastable 3C-SiC polytype is provided. In execution of the aforementioned method, the present invention also encompasses the use of a single crystal hexagonal-SiC domed substrate, and a method for manufacturing thereof. Said method for screening silicon carbide growth surfaces is comprised of: fabrication of a silicon carbide domed substrate; forming a step-terrace growth surface on the domed surface of said silicon carbide domed substrate by hydrogen etching; performing silicon carbide deposition upon said growth surface, thereby creating an silicon carbide epitaxial domed wafer; and characterization of said silicon carbide epitaxial domed wafer. Silicon carbide deposition upon a silicon carbide domed growth surface allows for the modulation of the supersaturation ratio under a single set of growth conditions. There is provided a method to select a specific off-cut angle and orientation for a silicon carbide substrate that can be used to selectively and homogeneously grow a targeted 3C-silicon carbide microstructure best suited for the intended application.

A high-throughput method for identifying single crystal hexagonal-SiC off-axis surfaces that support surface chemistries and kinetics to selectively produce various epitaxial growth modes of the metastable 3C-SiC polytype is provided. In execution of the aforementioned method, the present invention also encompasses the use of a single crystal hexagonal-SiC domed substrate, and a method for manufacturing thereof. Said method for screening silicon carbide growth surfaces is comprised of: fabrication of a silicon carbide domed substrate; forming a step-terrace growth surface on the domed surface of said silicon carbide domed substrate by hydrogen etching; performing silicon carbide deposition upon said growth surface, thereby creating an silicon carbide epitaxial domed wafer; and characterization of said silicon carbide epitaxial domed wafer. Silicon carbide deposition upon a silicon carbide domed growth surface allows for the modulation of the supersaturation ratio under a single set of growth conditions. There is provided a method to select a specific off-cut angle and orientation for a silicon carbide substrate that can be used to selectively and homogeneously grow a targeted 3C-silicon carbide microstructure best suited for the intended application.

A method of in-situ transfer during fabrication of a component comprising a 2-dimensional crystalline thin film on a substrate is disclosed. In one embodiment, the method includes forming a layered structure comprising a polymer, a 2-dimensional crystalline thin film, a metal catalyst, and a substrate. The metal catalyst, being a growth medium for the two-dimensional crystalline thin film, is etched and removed by infiltrating liquid to enable the in-situ transfer of the two-dimensional crystalline thin film directly onto the underlying substrate.

A method of in-situ transfer during fabrication of a component comprising a 2-dimensional crystalline thin film on a substrate is disclosed. In one embodiment, the method includes forming a layered structure comprising a polymer, a 2-dimensional crystalline thin film, a metal catalyst, and a substrate. The metal catalyst, being a growth medium for the two-dimensional crystalline thin film, is etched and removed by infiltrating liquid to enable the in-situ transfer of the two-dimensional crystalline thin film directly onto the underlying substrate.

Provided are a single crystal multi-element cathode material, a preparation method thereof, and a lithium-ion battery. The multi-element cathode material includes quasi single crystal particles each consisting of a plurality of crystal grains, and element G is present at grain boundaries between the plurality of crystal grains. A concentration of the element G at a g-site of the grain boundaries gradually decreases with an increase in a distance between the g-site and a surface of the quasi single crystal particles. The element G is selected from at least one of Ni, Co, Mn, Ta, Cr, Mo, W, La, Al, Y, Ti, Zr, V, Nb, Ce, Er, and B.

Provided are a single crystal multi-element cathode material, a preparation method thereof, and a lithium-ion battery. The multi-element cathode material includes quasi single crystal particles each consisting of a plurality of crystal grains, and element G is present at grain boundaries between the plurality of crystal grains. A concentration of the element G at a g-site of the grain boundaries gradually decreases with an increase in a distance between the g-site and a surface of the quasi single crystal particles. The element G is selected from at least one of Ni, Co, Mn, Ta, Cr, Mo, W, La, Al, Y, Ti, Zr, V, Nb, Ce, Er, and B.