A method of fabricating an ionic crystal includes providing a single crystal substrate of an ionic crystal material is provided. A patterned mask is applied over the single crystal substrate A growth solution is introduced over the single crystal substrate. The growth solution includes precursors for epitaxial growth of the ionic crystal material on the single crystal substrate such that epitaxial crystals grow over time through pattern openings in the patterned mask into a crystal structure with one or more morphologies.

GaN wafers and bulk crystal have dislocation density approximately 1/10 of dislocation density of seed used to form the bulk crystal and wafers. Masks are formed selectively on GaN seed dislocations, and new GaN grown on the seed has fewer dislocations and often 1/10 or less of dislocations present in seed.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

Disclosed is a building blocks method for low-cost fabrication of single crystal organometallic perovskite materials with pseudo crystallized hole transporting material layer. This method uses self-assembled molecular monolayers SAM as building blocks. This approach enables creation of defect-free perovskite crystals with desired morphology and crystallinity in a controlled way. Additionally, the crosslinked molecular layers SAM play a role of hole transporting materials HTM and encapsulation against diffusion of metal atoms and gas molecules, thus enhancing the stability of the perovskite materials. This method is cost effective and can be scaled up.

GaN wafers and bulk crystal have dislocation density approximately 1/10 of dislocation density of seed used to form the bulk crystal and wafers. Masks are formed selectively on GaN seed dislocations, and new GaN grown on the seed has fewer dislocations and often 1/10 or less of dislocations present in seed.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

Embodiments of the present disclosure include techniques related to techniques for processing materials for manufacture of group-III metal nitride and gallium based substrates. More specifically, embodiments of the disclosure include techniques for growing large area substrates using a combination of processing techniques. Merely by way of example, the disclosure can be applied to growing crystals of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others for manufacture of bulk or patterned substrates. Such bulk or patterned substrates can be used for a variety of applications including optoelectronic and electronic devices, lasers, light emitting diodes, solar cells, photo electrochemical water splitting and hydrogen generation, photodetectors, integrated circuits, and transistors, and others.

In various examples, an anode, which may be for a metal ion-conducting electrochemical device, comprises a metal member; and a metal conducting coating, which may be an epitaxial (e.g., a homoepitaxial) metal conducing coating, disposed on at least a portion of the metal member (e.g., all portions of the metal member that would be or are in contact with the electrolyte of the metal ion-conducting electrochemical device). A metal conducting coating or an anode may be formed by electrodeposition in the presence of a field.

A device for fabricating a crystalline conversion layer from a growth solution, has a first wall and a substrate defining between them a crystalline growth cavity; a device for inlet/outlet of the solution controlling, over time, at least the supply or extraction of the growth solution to and from the crystalline growth cavity; a heating device creating a temperature profile in the crystalline growth cavity, the substrate or the first wall; the temperature profile controlling a free formation of the crystalline conversion layer over a thickness of greater than 1 micrometer, in a direction mainly transverse to forming face; the whole of the thickness of the crystalline conversion layer being obtained by the free formation of the crystalline conversion layer.

A biaxially oriented SiC composite substrate includes a first biaxially oriented SiC layer that contains a threading screw dislocation and a basal plane dislocation, and a second biaxially oriented SiC layer that is formed continuously from the first biaxially oriented SiC layer and that contains 1×10.sup.16 atoms/cm.sup.3 or more and 1×10.sup.19 atoms/cm.sup.3 or less of a rare earth element. The defect density of a surface of the second biaxially oriented SiC layer is smaller than the defect density of the first biaxially oriented SiC layer.