Abstract: Shell-structured particles for sunscreen applications are provided herein. A method includes selecting one or more particles to serve as a core material in a sunscreen composition, wherein each of the one or more particles comprises a band gap within a predetermined range, and wherein said selecting is based on a desired absorption spectrum of the sunscreen composition; coating the one or more particles with at least one layer of zinc oxide. A composition includes selecting one or more particles to serve as a coating layer in a sunscreen composition, wherein each of the one or more particles comprises a band gap within a predetermined range, and wherein said selecting is based on a desired absorption spectrum of the sunscreen composition; and coating one or more zinc oxide particles with the one or more selected particles.

Abstract: Techniques for increasing grain size in AZTSSe absorber materials are provided. In one aspect, a method for forming an absorber film on a substrate includes: contacting the substrate with an Ag source, a Zn source, a Sn source, and an S source and/or an Se source under conditions sufficient to form the absorber film on the substrate having a target composition of: AgXZnYSn(S,Se)Z, wherein 1.7<x<2.2, 0.9<y<1.3, and 3.5<z<4.5, and including an amount of the Ag source that is from about 10% to about 30% greater than is needed to achieve the target composition; annealing the absorber film; and removing excess Ag from the absorber film. A solar cell and method for fabrication thereof are also provided.

Abstract: Zinc oxide compositions and methods for embedding oxide particles in a separate suspension particle for sunscreen applications are provided herein. A method includes reducing the size of each of multiple zinc oxide particles in accordance with a predetermined range; selecting one or more suspension particles to be utilized in conjunction with the multiple zinc oxide particles in a sunscreen composition, wherein each of the one or more suspension particles is larger in size than each of the multiple zinc oxide particles, and wherein said selecting is based on the refractive index of each of the one or more suspension particles; and embedding the multiple zinc oxide particles into the one or more suspension particles to create the sunscreen composition.

Abstract: Photovoltaic devices based on an Ag2ZnSn(S,Se)4 (AZTSSe) absorber and techniques for formation thereof are provided. In one aspect, a method for forming a photovoltaic device includes the steps of: coating a substrate with a conductive layer; contacting the substrate with an Ag source, a Zn source, a Sn source, and at least one of a S source and a Se source under conditions sufficient to form an absorber layer on the conductive layer having Ag, Zn, Sn, and at least one of S and Se; and annealing the absorber layer. Methods of doping the AZTSSe are provided. A photovoltaic device is also provided.

Abstract: Embodiments are directed to a memristive device. The memristive device includes a first conductive material layer. An oxide material layer is arranged on the first conductive layer. And a second conductive material layer is arranged on the oxide material layer, wherein the second conductive material layer comprises a metal-alkali alloy.

Abstract: A field effect transistor includes a carbon nanotube layer formed adjacent to a gate structure. Two intermetallic contacts are formed on the carbon nanotube layer. The two intermetallic contacts include an oxidation resistant compound having a work function below about 4.4 electron-volts.

Abstract: A field effect transistor includes a carbon nanotube layer formed adjacent to a gate structure. Two intermetallic contacts are formed on the carbon nanotube layer. The two intermetallic contacts include an oxidation resistant compound having a work function below about 4.4 electron-volts.

Abstract: Sunscreen additives for enhancing vitamin D production are provided herein. A method includes selecting phosphor materials to incorporate into zinc oxide particles, wherein the phosphor materials are capable of carrying out an up-conversion process whereby two or more photons absorbed by the zinc oxide particles and/or the phosphor materials within a first wavelength range are emitted as at least one photon within a second wavelength range. The method also includes incorporating the selected phosphor materials into the zinc oxide particles. A composition includes zinc oxide particles suspended within a medium of a sunscreen composition, and phosphor materials incorporated into the zinc oxide particles, wherein the phosphor materials are capable of carrying out an up-conversion process whereby two or more photons absorbed by the zinc oxide particles and/or the phosphor materials within a first wavelength range are emitted as at least one photon within a second wavelength range.

Abstract: A method of preparing a Ag2ZnSn(S,Se)4 compound, including dissolving selenourea (SeC(NH2)2) in an aprotic solvent, and dissolving a silver salt, a zinc salt, and a tin salt in the aprotic solvent with the selenourea to form a metal solution; and coating the metal solution onto a substrate to form an Ag2ZnSn(S,Se)4 compound layer on the substrate.

Abstract: Techniques for forming a transparent conducting oxide (TCO) top contact using a low temperature process are provided. In one aspect of the invention, a method of forming a TCO on a substrate is provided. The method includes the steps of: generating a source gas of the TCO using e-beam evaporation; generating atomic oxygen using RF plasma; and contacting the substrate with the TCO source gas and the atomic oxygen under conditions sufficient to form the TCO on the substrate. A photovoltaic device is also provided which includes a bottom cell; and a perovskite-based top cell on the kesterite-based bottom cell. The perovskite-based top cell includes a top electrode formed from a TCO.

Abstract: Silver-containing absorbers for photovoltaic devices and techniques for fabrication thereof are provided. In one aspect, a method of forming an ink includes: mixing a silver halide and a solvent to form a first solution; mixing a metal, sulfur, and the solvent to form a second solution; combining the first solution and the second solution to form a precursor solution; and adding constituent components for an absorber material to the precursor solution to form the ink. Methods of forming an absorber film, a photovoltaic device, and the resulting photovoltaic device are also provided.

Abstract: Zinc oxide compositions as well as techniques for doping ZnO particles for sunscreen applications are provided herein. A method includes selecting one or more dopants to be incorporated into one or more zinc oxide particles in a sunscreen composition, wherein the one or more dopants comprise chromium, cobalt, gallium, and/or tin, and wherein said selecting is based on one or more optical properties associated with each of the dopants, and incorporating the selected dopants into the zinc oxide particles to create the sunscreen composition. A composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition, and one or more dopants incorporated into each of the multiple zinc oxide particles, wherein the one or more dopants comprise chromium, cobalt, gallium, and/or tin, and wherein each of the dopants imparts one or more optical properties to the zinc oxide particle within which the dopant is incorporated.

Abstract: In one aspect, a spectrometer insert is provided. The spectrometer insert includes: an enclosed housing; a first transparent window on a first side of the enclosed housing; a second transparent window on a second side of the enclosed housing, wherein the first side and the second side are opposing sides of the enclosed housing; and a sample mounting and heating assembly positioned within an interior cavity of the enclosed housing in between, and in line of sight of, the first transparent window and the second transparent window. A method for using the spectrometer insert to locally heat a sample so as to measure temperature-dependent optical properties of the sample is also provided.

Abstract: Zinc oxide compositions and methods for applying anti-reflective coating on oxide particles for sunscreen applications are provided herein. A method includes selecting one or more coating materials to be applied to zinc oxide particles in a sunscreen composition, wherein said selecting is based on optical properties of the coating materials, wherein the optical properties comprises at least the refractive index of each of the coating materials, and applying the selected coating materials to the zinc oxide particles to create the sunscreen composition.

Abstract: Zinc oxide compositions and methods for applying anti-reflective coating on oxide particles for sunscreen applications are provided herein. A composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition, and two or more coating materials applied to each of the multiple zinc oxide particles in distinct layers via a gradation based on refractive index, wherein each of the coating materials has a refractive index that is between the refractive index of air and the refractive index of zinc oxide, and wherein the two or more coating materials comprise zinc sulfide and titanium dioxide.

Abstract: Techniques for solar thermal water purification by recycling photovoltaic reflection losses are provided. In one aspect, a solar thermal water purification system includes: a water purification component for desalinating salt water, the water purification component having multiple stages through which the salt water passes, and condensers in each of the stages; and a photovoltaic component configured to heat the salt water prior to the salt water entering a first stage of the water purification component, wherein desalinated water evaporates and condenses in each of the stages to be collected as pure water. A system using reverse osmosis and a heat-driven water pump is also provided. Methods for water purification are also provided.

Abstract: Zinc oxide compositions and methods for applying anti-reflective coating on oxide particles for sunscreen applications are provided herein. A composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition, and two or more coating materials applied to each of the multiple zinc oxide particles in distinct layers via a gradation based on refractive index, wherein each of the coating materials has a refractive index that is between the refractive index of air and the refractive index of zinc oxide, and wherein the two or more coating materials comprise one or more fluoropolymers and aluminum oxide.

Abstract: Zinc oxide compositions and methods for applying anti-reflective coating on oxide particles for sunscreen applications are provided herein. A composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition, and coating materials applied to each of the multiple zinc oxide particles in distinct layers via a gradation based on refractive index, wherein each of the coating materials has a refractive index that is between the refractive index of air and the refractive index of zinc oxide, and wherein the coating materials comprise a combination of (i) silicon dioxide, (ii) magnesium fluoride, (iii) one or more fluoropolymers, (iv) aluminum oxide, (v) zinc sulfide, and (vi) titanium dioxide.

Abstract: Zinc oxide compositions and methods for applying anti-reflective coating on oxide particles for sunscreen applications are provided herein. A method includes selecting two or more coating materials to be applied to zinc oxide particles in a sunscreen composition, wherein said selecting is based on optical properties of the coating materials, wherein the optical properties comprises at least the refractive index of each of the coating materials, and applying the selected coating materials to the zinc oxide particles to create the sunscreen composition.

Abstract: Zinc oxide compositions as well as techniques for doping ZnO particles for sunscreen applications are provided herein. A method includes selecting one or more dopants to be incorporated into one or more zinc oxide particles in a sunscreen composition, wherein said selecting is based on one or more optical properties associated with each of the dopants, and incorporating the selected dopants into the zinc oxide particles to create the sunscreen composition.