Abstract: Aluminum oxide (Al2O3) thin films having a high ?-phase purity and low defect density and methods for making the aluminum oxide thin films are provided. Also provided are epitaxial heterostructures that incorporate the aluminum oxide thin films as growth substrates and methods of forming the heterostructures. The Al2O3 films are pure, or nearly pure, ?-Al2O3. As such, the films contain no, or only a very low concentration of, other Al2O3 polymorph phases. In particular, the Al2O3 films contain no, or only a very low concentration of, the ?-Al2O3 polymorph phase.

Abstract: A method for crystallizing an amorphous multicomponent ionic compound comprises applying an external stimulus to a layer of an amorphous multicomponent ionic compound, the layer in contact with an amorphous surface of a deposition substrate at a first interface and optionally, the layer in contact with a crystalline surface at a second interface, wherein the external stimulus induces an amorphous-to-crystalline phase transformation, thereby crystallizing the layer to provide a crystalline multicomponent ionic compound, wherein the external stimulus and the crystallization are carried out at a temperature below the melting temperature of the amorphous multicomponent ionic compound. If the layer is in contact with the crystalline surface at the second interface, the temperature is further selected to achieve crystallization from the crystalline surface via solid phase epitaxial (SPE) growth without nucleation.

Abstract: Transparent, electrically conductive vanadium oxide-based perovskite films and methods of making the vanadium oxide-based perovskite films are provided. Transparent conducting vanadate perovskites are made by forming a layer of amorphous vanadate perovskite precursor around a plurality of nanoscale, crystalline, perovskite oxide seeds and heating the layer of amorphous vanadate perovskite precursor at a temperature that favors lateral vanadate perovskite crystal growth from the perovskite oxide seeds over homogeneous crystal nucleation within the layer of amorphous vanadate perovskite precursor material. The crystallization processes can form the desired vanadate perovskite phase directly or via a transformation in a controlled gas environment from an initial crystallized vanadate perovskite phase that has a higher oxidation state.

Abstract: A method for crystallizing an amorphous multicomponent ionic compound comprises applying an external stimulus to a layer of an amorphous multicomponent ionic compound, the layer in contact with an amorphous surface of a deposition substrate at a first interface and optionally, the layer in contact with a crystalline surface at a second interface, wherein the external stimulus induces an amorphous-to-crystalline phase transformation, thereby crystallizing the layer to provide a crystalline multicomponent ionic compound, wherein the external stimulus and the crystallization are carried out at a temperature below the melting temperature of the amorphous multicomponent ionic compound. If the layer is in contact with the crystalline surface at the second interface, the temperature is further selected to achieve crystallization from the crystalline surface via solid phase epitaxial (SPE) growth without nucleation.

Abstract: A method for crystallizing an amorphous multicomponent ionic compound comprises applying an external stimulus to a layer of an amorphous multicomponent ionic compound, the layer in contact with an amorphous surface of a deposition substrate at a first interface and optionally, the layer in contact with a crystalline surface at a second interface, wherein the external stimulus induces an amorphous-to-crystalline phase transformation, thereby crystallizing the layer to provide a crystalline multicomponent ionic compound, wherein the external stimulus and the crystallization are carried out at a temperature below the melting temperature of the amorphous multicomponent ionic compound. If the layer is in contact with the crystalline surface at the second interface, the temperature is further selected to achieve crystallization from the crystalline surface via solid phase epitaxial (SPE) growth without nucleation.

Abstract: A Hydride Vapor Phase Epitaxy (HVPE) system is provided which comprises a deposition assembly comprising a plurality of deposition chambers and a plurality of separation chambers mounted together, each separation chamber having two opposing ends, each end mounted to a deposition chamber of the plurality of deposition chambers and in fluid communication with the deposition chamber via a fluid pathway, wherein each deposition chamber of the plurality of deposition chambers defines a deposition zone having a height hd, each separation chamber defines a separation zone having a height hs and a length ls, and each fluid pathway has a height hfp, wherein hfp, hs and ls are selected to provide a predetermined interfacial transition region value between different material layers of a multilayer heterostructure; and a moveable belt configured to continuously convey a substrate mounted thereon through the plurality of deposition chambers and the plurality of separation chambers.

Abstract: High-quality, single-crystalline silicon-germanium (Si(1-x)Gex) having a high germanium content is provided. Layers of the high-quality, single-crystalline silicon-germanium can be grown to high sub-critical thicknesses and then released from their growth substrates to provide Si(1-x)Gex films without lattice mismatch-induced misfit dislocations or a mosaic distribution of crystallographic orientations.

Abstract: High-quality, single-crystalline silicon-germanium (Si(1-x)Gex) having a high germanium content is provided. Layers of the high-quality, single-crystalline silicon-germanium can be grown to high sub-critical thicknesses and then released from their growth substrates to provide Si(1-x)Gex films without lattice mismatch-induced misfit dislocations or a mosaic distribution of crystallographic orientations.