Abstract: A method for making a selective-area lift-off thin film comprises depositing a van der Waals (vdW) buffer on a substrate; depositing a thin film material (or device structure) on the van der Waals buffer; depositing an adhesion layer on the thin film material; forming a stressor layer on top of the thin film layer; and bonding a handle layer to the stressor layer. Force may be applied to the layered structure by one or more of rolling, bending, and shearing. The area selected for lift-off may be defined by one of laser cutting and mechanical scribing. The vdW buffer includes one or more of hBN, graphite, and graphene. The handle layer is a one of a polyimide tape, thermal release tape, UV release tape, water- or solvent-soluble tape, Kapton tape, and Scotch tape. The stressor layer is a metal film, e.g. Ni, Cr, Ti.

Abstract: A method for making a selective-area lift-off thin film comprises depositing a van der Waals (vdW) buffer on a substrate; depositing a thin film material (or device structure) on the van der Waals buffer; depositing an adhesion layer on the thin film material; forming a stressor layer on top of the thin film layer; and bonding a handle layer to the stressor layer. Force may be applied to the layered structure by one or more of rolling, bending, and shearing. The area selected for lift-off may be defined by one of laser cutting and mechanical scribing. The vdW buffer includes one or more of hBN, graphite, and graphene. The handle layer is a one of a polyimide tape, thermal release tape, UV release tape, water- or solvent-soluble tape, Kapton tape, and Scotch tape. The stressor layer is a metal film, e.g. Ni, Cr, Ti.

Abstract: Systems, methods and apparatus incorporating Gallium Nitride heterostructure (Alx,Iny)Ga1-x-y N-materials in flexible, strainable and wearable radio frequency devices. These devices include (Alx,Iny)Ga1-x-y N-based high-electron mobility transistors (HEMTs), which enable amplification of microwave radio frequencies from approximately 300 MHz to approximately 300 GHz for flexible and conformal wireless transmission.

Abstract: A method of forming a sp2 boron nitride (BN) layer on a surface of a substrate, the method comprising providing first and second precursors at the surface of the substrate, the first precursor being a source of boron and the second precursor being a source of nitrogen; heating the substrate to a temperature greater than a pyrolysis point for either of the first and second precursors; pyrolyzing the first precursor at the surface of the substrate; activating the second precursor at the surface of the substrate with the pyrolyzed first precursor; and adsorbing the pyrolyzed first precursor and the activated second precursor onto the surface of the substrate.

Abstract: A low pressure process for producing thin film crystalline black phosphorus on a substrate and a black phosphorus thin film made by the process. The process includes flowing a phosphorus-containing gas into a deposition chamber and depositing phosphorus from the phosphorus-containing gas onto the substrate in the chamber. The substrate is selected from (i) a gold substrate, a gold-tin alloy substrate, a silver substrate and a copper substrate and (ii) a substrate comprising a thin film of metal selected from gold, tin, silver, copper and alloys of the foregoing metals. The substrate and phosphorus are heated to a temperature ranging from about 350° to less than about 500° C. to form a phosphorus intermediate composition. The substrate and intermediate composition are heated to a temperature of greater than 500° C. to less than about 1000° C. convert the metal phosphorus intermediate composition to the black phosphorus thin film.

Abstract: A low pressure process for producing thin film crystalline black phosphorus on a substrate and a black phosphorus thin film made by the process. The process includes flowing a phosphorus-containing gas into a deposition chamber and depositing phosphorus from the phosphorus-containing gas onto the substrate in the chamber. The substrate is selected from (i) a gold substrate, a gold-tin alloy substrate, a silver substrate and a copper substrate and (ii) a substrate comprising a thin film of metal selected from gold, tin, silver, copper and alloys of the foregoing metals. The substrate and phosphorus are heated to a temperature ranging from about 350° to less than about 500° C. to form a phosphorus intermediate composition. The substrate and intermediate composition are heated to a temperature of greater than 500° C. to less than about 1000° C. convert the metal phosphorus intermediate composition to the black phosphorus thin film.

Abstract: A low pressure process for producing thin film crystalline black phosphorus on a substrate and a black phosphorus thin film made by the process. The process includes flowing a phosphorus-containing gas into a deposition chamber and depositing phosphorus from the phosphorus-containing gas onto the substrate in the chamber. The substrate is selected from (i) a gold substrate, a gold-tin alloy substrate, a silver substrate and a copper substrate and (ii) a substrate comprising a thin film of metal selected from gold, tin, silver, copper and alloys of the foregoing metals. The substrate and phosphorus are heated to a temperature ranging from about 350° to less than about 500° C. to form a phosphorus intermediate composition. The substrate and intermediate composition are heated to a temperature of greater than 500° C. to less than about 1000° C. convert the metal phosphorus intermediate composition to the black phosphorus thin film.

Abstract: Systems, methods and apparatus incorporating Gallium Nitride heterostructure (Alx,Iny)Ga1-x-y N-materials in flexible, strainable and wearable radio frequency devices. These devices include (Alx,Iny)Ga1-x-y N-based high-electron mobility transistors (HEMTs), which enable amplification of microwave radio frequencies from approximately 300 MHz to approximately 300 GHz for flexible and conformal wireless transmission.

Abstract: A semiconductor device includes a mechanical release layer, such as a van der Waals buffer layer, with a predetermined material roughness and thickness adjacent to a first substrate; a nucleation layer adjacent to the mechanical release layer; and a first semiconductor layer attached to the nucleation layer. The first semiconductor layer, the nucleation layer, and a portion of the mechanical release layer are releasably connected to the first substrate. The predetermined material roughness and thickness of the mechanical release layer determines a bonding strength of the first semiconductor layer to the first substrate. The semiconductor device may include an aluminum nitride insert layer adjacent to the first semiconductor layer; an aluminum gallium nitride barrier layer adjacent to the aluminum nitride insert layer; and a second semiconductor layer adjacent to the aluminum gallium nitride barrier layer.

Abstract: A method of synthesizing zinc selenide crystals. The method includes forming an aqueous growth medium by combining a mineralizer solution of an alkali nutrient with a feedstock including zinc and selenium. A seed crystal is added to the growth medium. The aqueous growth medium and seed crystal are pressurized and a thermal gradient applied such that a temperature of a first portion of the aqueous growth medium is greater than a second portion of the aqueous growth medium. The zinc and selenium are dissolved into the mineralizer solution from the feedstock in the first portion of the aqueous growth medium and spontaneously forms at least one single crystal of zinc selenide on the seed crystal in the first portion of the aqueous growth medium.

Abstract: A semiconductor device includes a mechanical release layer, such as a van der Waals buffer layer, with a predetermined material roughness and thickness adjacent to a first substrate; a nucleation layer adjacent to the mechanical release layer; and a first semiconductor layer attached to the nucleation layer. The first semiconductor layer, the nucleation layer, and a portion of the mechanical release layer are releasably connected to the first substrate. The predetermined material roughness and thickness of the mechanical release layer determines a bonding strength of the first semiconductor layer to the first substrate. The semiconductor device may include an aluminum nitride insert layer adjacent to the first semiconductor layer; an aluminum gallium nitride barrier layer adjacent to the aluminum nitride insert layer; and a second semiconductor layer adjacent to the aluminum gallium nitride barrier layer.

Abstract: A method of synthesizing zinc selenide crystals. The method includes forming an aqueous growth medium by combining a mineralizer solution of an alkali nutrient with a feedstock including zinc and selenium. A seed crystal is added to the growth medium. The aqueous growth medium and seed crystal are pressurized and a thermal gradient applied such that a temperature of a first portion of the aqueous growth medium is greater than a second portion of the aqueous growth medium. The zinc and selenium are dissolved into the mineralizer solution from the feedstock in the first portion of the aqueous growth medium and spontaneously forms at least one single crystal of zinc selenide on the seed crystal in the first portion of the aqueous growth medium.

Abstract: The present invention provides methods of forming metal oxide semiconductor nanostructures and, in particular, zinc oxide (ZnO) semiconductor nanostructures, possessing high surface area, plant-like morphologies on a variety of substrates. Optoelectronic devices, such as photovoltaic cells, incorporating the nanostructures are also provided.

Abstract: The present invention provides methods of forming metal oxide semiconductor nanostructures and, in particular, zinc oxide (ZnO) semiconductor nanostructures, possessing high surface area, plant-like morphologies on a variety of substrates. Optoelectronic devices, such as photovoltaic cells, incorporating the nanostructures are also provided.

Abstract: The present invention provides methods of forming metal oxide semiconductor nanostructures and, in particular, zinc oxide (ZnO) semiconductor nanostructures, possessing high surface area, plant-like morphologies on a variety of substrates. Optoelectronic devices, such as photovoltaic cells, incorporating the nanostructures are also provided.

Abstract: The present invention provides methods of forming metal oxide semiconductor nanostructures and, in particular, zinc oxide (ZnO) semiconductor nanostructures, possessing high surface area, plant-like morphologies on a variety of substrates. Optoelectronic devices, such as photovoltaic cells, incorporating the nanostructures are also provided.