Abstract: Systems and methods for growth of silicon carbide over a layer comprising graphene and/or hexagonal boron nitride, and related articles, are generally described. In some embodiments, a SiC film is fabricated over a layer comprising graphene and/or hexagonal boron nitride, which in turn is disposed over a substrate. The layer and/or the substrate may be lattice-matched with the SiC film to reduce defect density in the SiC film. The fabricated SiC film may then be removed from the substrate via, for example, a stressor attached to the SiC film. In certain cases, the layer serves as a reusable platform for growing SiC films and also serves a release layer that allows fast, precise, and repeatable release at the layer surface.

Abstract: A sensitive and selective, in-line method to measure and validate the sulfur content at ppb levels in both the liquid and gas phase of an analyte. The method includes patterning graphene, for example to form a mesa structure comprising horizontal or vertical lines or an array of multidentate star features; functionalizing the patterned graphene and attaching nanoparticles to the functionalized graphene to form a device; exposing the device to an analyte in the gas or liquid phase; detecting a change in electrical response when sulfur is present in the analyte; and recovering the device for future use. Also disclosed is the related sulfur detector.

Abstract: A method of fabricating suspended beam silicon carbide microelectromechanical (MEMS) structure with low capacitance and good thermal expansion match. A suspended material structure is attached to an anchor material structure that is direct wafer bonded to a substrate. The anchor material structure and the suspended material structure are formed from either a hexagonal single-crystal SiC material, and the anchor material structure is bonded to the substrate while the suspended material structure does not have to be attached to the substrate. The substrate may be a semi-insulating or insulating SiC substrate. The substrate may have an etched recess region on the substrate first surface to facilitate the formation of the movable suspended material structures. The substrate may have patterned electrical electrodes on the substrate first surface, within recesses etched into the substrate.

Abstract: A method for graphene functionalization that preserves electronic properties and enables nanoparticles deposition comprising providing graphene, functionalizing the graphene via non-covalent or covalent functionalization, rinsing the graphene, drying the graphene, and forming functionalized graphene wherein the functionalized graphene preserves electronic properties and enables nanoparticles deposition. A functionalized graphene wherein the graphene functionalization preserves electronic properties and enables nanoparticles deposition.

Abstract: A sensitive and selective, in-line method to measure and validate the sulfur content at ppb levels in both the liquid and gas phase of an analyte. The method includes patterning graphene, for example to form a mesa structure comprising horizontal or vertical lines or an array of multidentate star features; functionalizing the patterned graphene and attaching nanoparticles to the functionalized graphene to form a device; exposing the device to an analyte in the gas or liquid phase; detecting a change in electrical response when sulfur is present in the analyte; and recovering the device for future use. Also disclosed is the related sulfur detector.

Abstract: Systems and methods for growth of silicon carbide over a layer comprising graphene and/or hexagonal boron nitride, and related articles, are generally described. In some embodiments, a SiC film is fabricated over a layer comprising graphene and/or hexagonal boron nitride, which in turn is disposed over a substrate. The layer and/or the substrate may be lattice-matched with the SiC film to reduce defect density in the SiC film. The fabricated SiC film may then be removed from the substrate via, for example, a stressor attached to the SiC film. In certain cases, the layer serves as a reusable platform for growing SiC films and also serves a release layer that allows fast, precise, and repeatable release at the layer surface.

Abstract: A sensitive and selective, in-line method to measure and validate the sulfur content at ppb levels in both the liquid and gas phase of fuel. The method includes etching graphene, for example to form a mesa structure comprising horizontal or vertical lines or an array of multidentate star features; functionalizing the etched graphene and attaching metal oxide nanoparticles to the functionalized graphene to form a device; exposing the device to a fuel in the gas or liquid phase; detecting a change in conductivity when sulfur is present in the fuel; and recovering the device for future use. Also disclosed is the related in-line graphene-based ppb level sulfur detector for fuels.

Abstract: An electrochemical cell includes a working electrode in contact with an aqueous electrolyte solution, a counter electrode in contact with the aqueous electrolyte solution, and a reference electrode in contact with the aqueous electrolyte solution. The working electrode comprises a plasma modified epitaxial synthesized graphene surface fabricated on SiC.

Abstract: A method of fabricating suspended beam silicon carbide microelectromechanical (MEMS) structure with low capacitance and good thermal expansion match. A suspended material structure is attached to an anchor material structure that is direct wafer bonded to a substrate. The anchor material structure and the suspended material structure are formed from either a hexagonal single-crystal SiC material, and the anchor material structure is bonded to the substrate while the suspended material structure does not have to be attached to the substrate. The substrate may be a semi-insulating or insulating SiC substrate. The substrate may have an etched recess region on the substrate first surface to facilitate the formation of the movable suspended material structures. The substrate may have patterned electrical electrodes on the substrate first surface, within recesses etched into the substrate.

Abstract: Electromechanical device structures are provided, as well as methods for forming them. The device structures incorporate at least a first and second substrate separated by an interface material layer, where the first substrate comprises an anchor material structure and at least one suspended material structure, optionally a spring material structure, and optionally an electrostatic sense electrode. The device structures may be formed by methods that include providing an interface material layer on one or both of the first and second substrates, bonding the interface materials to the opposing first or second substrate or to the other interface material layer, followed by forming the suspended material structure by etching.

Abstract: Electromechanical device structures are provided, as well as methods for forming them. The device structures incorporate at least a first and second substrate separated by an interface material layer, where the first substrate comprises an anchor material structure and at least one suspended material structure, optionally a spring material structure, and optionally an electrostatic sense electrode. The device structures may be formed by methods that include providing an interface material layer on one or both of the first and second substrates, bonding the interface materials to the opposing first or second substrate or to the other interface material layer, followed by forming the suspended material structure by etching.

Abstract: Electromechanical device structures are provided, as well as methods for forming them. The device structures incorporate at least a first and second substrate separated by an interface material layer, where the first substrate comprises an anchor material structure and at least one suspended material structure, optionally a spring material structure, and optionally an electrostatic sense electrode. The device structures may be formed by methods that include providing an interface material layer on one or both of the first and second substrates, bonding the interface materials to the opposing first or second substrate or to the other interface material layer, followed by forming the suspended material structure by etching.

Abstract: A method of growing crystalline materials on two-dimensional inert materials comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material. A crystalline material grown on a two-dimensional inert material made from the process comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material.

Abstract: Material structures and methods for etching hexagonal, single-crystal silicon carbide (SiC) materials are provided, which include selection of on-axis or near on-axis hexagonal single-crystal SiC material as the material to be etched. The methods include etching of SiC bulk substrate material, etching of SiC material layers bonded to a silicon oxide layer, etching of suspended SiC material layers, and etching of a SiC material layer anodically bonded to a glass layer. Plasma-etched hexagonal single-crystal SiC materials of the invention may be used to form structures that include, but are not limited to, microelectromechanical beams, microelectromechanical membranes, microelectromechanical cantilevers, microelectromechanical bridges, and microelectromechanical field effect transistor devices.

Abstract: A method of growing crystalline materials on two-dimensional inert materials comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material. A crystalline material grown on a two-dimensional inert material made from the process comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material.

Abstract: A method of growing crystalline materials on two-dimensional inert materials comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material. A crystalline material grown on a two-dimensional inert material made from the process comprising functionalizing a surface of a two-dimensional inert material, growing a nucleation layer on the functionalized surface, and growing a crystalline material.

Abstract: A sensitive and selective, in-line method to measure and validate the sulfur content at ppb levels in both the liquid and gas phase of fuel. The method includes etching graphene, for example to form a mesa structure comprising horizontal or vertical lines or an array of multidentate star features; functionalizing the etched graphene and attaching metal oxide nanoparticles to the functionalized graphene to form a device; exposing the device to a fuel in the gas or liquid phase; detecting a change in conductivity when sulfur is present in the fuel; and recovering the device for future use. Also disclosed is the related in-line graphene-based ppb level sulfur detector for fuels.

Abstract: A method of: providing an off-axis silicon carbide substrate, and etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.

Abstract: A method of: providing an off-axis 4H—SiC substrate, and etching the surface of the substrate with hydrogen or an inert gas.

Abstract: An electrochemical cell includes a working electrode in contact with an aqueous electrolyte solution, a counter electrode in contact with the aqueous electrolyte solution, and a reference electrode in contact with the aqueous electrolyte solution. The working electrode comprises a plasma modified epitaxial synthesized graphene surface fabricated on SiC.