Abstract: Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.

Abstract: Systems for measuring a distance include a lens positioned a distance above a target surface. A camera is configured to measure a first interference pattern between the lens and the target surface using a light source at a first wavelength and to measure a second interference pattern between the lens and the target surface using a light source at a second wavelength. A processor is configured to determine an absolute measurement of the distance between the lens and the target surface based on the first interference pattern and the second interference pattern.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.

Abstract: A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu—Zn—Sn—S(Se)(CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Abstract: Aspects relate to a system and a method of operating an integrated device is provided. The method includes providing a circuit board that includes one or more on-board electronic components and an upper surface configured as a substrate, providing photovoltaic device layers that include at least a semi-conductor absorber layer, a buffer layer, and a top electrode layer on the upper surface of the circuit board that form a photovoltaic device using the upper surface of the circuit board as a photovoltaic device substrate, wherein the buffer layer is integrally deposited between the semi-conductor absorber layer and the top electrode, generating electricity using the photovoltaic device, and powering one or more of the on-board electronic components using the electricity from the photovoltaic device.

Abstract: Aspects relate to a system and a method of manufacturing an integrated device. The method includes providing a circuit board, configuring an upper surface of the circuit board as a substrate, integrally depositing photovoltaic device layers that include at least a semi-conductor absorber layer, a buffer layer, and a top electrode layer on the upper surface of the circuit board to form a photovoltaic device using the upper surface of the circuit board as a photovoltaic device substrate, wherein the buffer layer is integrally deposited between the semi-conductor absorber layer and the top electrode, and electrically connecting the photovoltaic device to one or more on-board electronic components.

Abstract: Systems for measuring a distance include a lens positioned a distance above a target surface. A camera is configured to measure a first interference pattern between the lens and the target surface using a light source at a first wavelength and to measure a second interference pattern between the lens and the target surface using a light source at a second wavelength. A processor is configured to determine an absolute measurement of the distance between the lens and the target surface based on the first interference pattern and the second interference pattern.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.

Abstract: A force detector and method for using the same includes a lens. A cantilever is disposed below the movable lens. A laser is disposed above the movable lens and is configured to emit a beam of light that reflects from a surface of the lens and the cantilever. A processor is configured to determine a force between the movable lens and the cantilever based on a change in phase in images produced by the light reflected from the spherical surface and the light reflected from the cantilever.

Abstract: Techniques for selective placement of carbon nanotubes using bifunctional acid monolayers are provided. In one aspect, a method for selective placement of carbon nanotubes on a metal oxide surface includes the steps of: dispersing poly-fluorene polymer-wrapped carbon nanotubes in an organic solvent; creating a patterned monolayer of a bifunctional acid on the metal oxide surface, wherein the bifunctional acid comprises a first acid functional group for binding to the metal oxide surface, and a second acid functional group for binding to the poly-fluorene polymer-wrapped carbon nanotubes; and contacting the poly-fluorene polymer-wrapped carbon nanotubes dispersed in the organic solvent with the patterned monolayer of the bifunctional acid on the metal oxide surface to selectively place the carbon nanotubes on the metal oxide surface via the patterned monolayer of the bifunctional acid. A carbon nanotube-based device and method of formation thereof are also provided.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.

Abstract: A force detector and method for using the same includes a lens. A cantilever is below the movable lens. A laser above the movable lens emits a beam of light through the movable lens, such that light reflects from the lens and the cantilever. A camera is configured to capture images produced by the light reflected from the lens and the light reflected from the cantilever. A processor is configured to determine a force between the movable lens and the cantilever based on a change in phase of the interference rings.

Abstract: Techniques for selective placement of carbon nanotubes using bifunctional acid monolayers are provided. In one aspect, a method for selective placement of carbon nanotubes on a metal oxide surface includes the steps of: dispersing poly-fluorene polymer-wrapped carbon nanotubes in an organic solvent; creating a patterned monolayer of a bifunctional acid on the metal oxide surface, wherein the bifunctional acid comprises a first acid functional group for binding to the metal oxide surface, and a second acid functional group for binding to the poly-fluorene polymer-wrapped carbon nanotubes; and contacting the poly-fluorene polymer-wrapped carbon nanotubes dispersed in the organic solvent with the patterned monolayer of the bifunctional acid on the metal oxide surface to selectively place the carbon nanotubes on the metal oxide surface via the patterned monolayer of the bifunctional acid. A carbon nanotube-based device and method of formation thereof are also provided.

Abstract: Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.

Abstract: A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Abstract: A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Abstract: An integrated kesterite (e.g., CZT(S,Se)) photovoltaic device and battery is provided. In one aspect, a method of forming an integrated photovoltaic device and battery includes: forming a photovoltaic device having a substrate, an electrically conductive layer, an absorber layer, a buffer layer, a transparent front contact, and a metal grid; removing the substrate and the electrically conductive layer from the photovoltaic device to expose a backside surface of the absorber layer; forming at least one back contact on the backside surface of the absorber layer; and integrating the photovoltaic device with a battery, wherein the integrating includes connecting i) a positive contact of the battery with the back contact on the backside surface of the absorber layer and ii) a negative contact of the battery with the metal grid on the transparent front contact. An integrated photovoltaic device and battery is also provided.

Abstract: A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Abstract: A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.