Abstract: Shell-structured particles for sunscreen applications are provided herein. A composition includes one or more zinc oxide particles constituting a core material in a sunscreen composition, one or more particles coating the one or more zinc oxide particles, wherein each of the one or more particles comprises a band gap within a predetermined range, and wherein said one or more particles are selected based on a desired absorption spectrum of the sunscreen composition, and an anti-reflective coating applied to the surface of the one or more particles coating the one or more zinc oxide particles.

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.

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.

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: A method and apparatus for manufacturing a nitrogen-doped CZTSSe layer for a solar cell is disclosed. A substrate is mounted in a vacuum chamber. A plurality of effusion cells are placed within the vacuum chamber in order to evaporate copper, zinc, tin, sulfur, and/or selenium to form elemental vapors in a region proximate the substrate. An RF-based nitrogen source delivers a nitrogen plasma in the region proximal to the substrate. The elemental vapors and the nitrogen plasma form a gas mixture in the region near the substrate, which then react at the substrate to form a CZTSSe absorber layer for a solar cell.

Abstract: Notch filter coatings for use in sunscreen applications are provided herein. An exemplary composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition; and a combination of multiple notch filter coating materials individually applied as a distinct layer to each of the multiple zinc oxide particles to create a multi-layered structure surrounding each of the multiple zinc oxide particles within the sunscreen composition, wherein the multi-layered structure: reflects light at a user-determined wavelength range based on the wavelength range at which each of the multiple notch filter coating materials reflects light; and allows wavelengths of light (i) within at least a portion of the ultraviolet spectrum and (ii) outside of the user-determined wavelength range to be absorbed by the multiple zinc oxide particles.

Abstract: Notch filter coatings for use in sunscreen applications are provided herein. An exemplary composition includes multiple zinc oxide particles suspended within a medium forming sunscreen composition; and a combination of multiple notch filter coating materials individually applied as a distinct layer to each of the multiple zinc oxide particles to create a multi-layered structure surrounding each of the multiple zinc oxide particles within the sunscreen composition, wherein the multi-layered structure: reflects light at a user-determined wavelength range based on the wavelength range at which each of the multiple notch filter coating materials reflects light; and allows wavelengths of light (i) within at least a portion of the ultraviolet spectrum and (ii) outside of the user-determined wavelength range to be absorbed by the multiple zinc oxide particles.

Abstract: Techniques for implementing organic materials in sunscreen applications are provided herein. A method includes selecting a combination of multiple organic materials to incorporate into a sunscreen composition, wherein said selecting is based on (i) a desired absorption spectrum of the sunscreen composition, (ii) the absorption spectrum of each of the multiple organic materials, and (iii) a particle size limitation for each of the multiple organic materials, and incorporating the selected combination of organic materials into the sunscreen composition to generate the desired absorption spectrum. A composition includes a combination of multiple organic materials incorporated into a sunscreen composition, wherein the combination of organic materials is selected based on (i) a desired absorption spectrum of the sunscreen composition, (ii) the absorption spectrum of each of the multiple organic materials, and (iii) a particle size limitation for each of the multiple organic materials.

Abstract: After forming a layer of a Cu-deficient kesterite compound having the formula Cu2-xZn1+xSn(SySe1-y)4, wherein 0<x<1, and 0?y?1, on a substrate and forming a Ag layer on the Cu-deficient kesterite compound layer, the Cu-deficient kesterite compound layer and Ag layer are annealed in a S- and/or Se-rich ambient to provide a film containing a Ag—Cu mixed kesterite compound having the formula AgxCu2-xZnSn(SySe1-y)4, wherein 0<x<2, and 0?y?1.

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: A photovoltaic device with an improved n-type partner and a method for making the same. The device includes: a transparent substrate; a transparent conductive electrode layer disposed on the transparent substrate; an n-type layer of Zn1-xMgxO, wherein 0<x?1, disposed on the transparent conductive electrode layer; a chalcogen absorber layer disposed on the n-type layer; and a conductive layer disposed on the chalcogen absorber layer. The method includes: forming a transparent conductive electrode layer on a transparent substrate; forming an n-type layer of Zn1-xMgxO, wherein 0<x?1, on the transparent conductive electrode layer; forming a chalcogen absorber layer on the n-type layer; forming a conductive layer on the chalcogen absorber layer; and annealing to form the device. Another device having a superstrate configuration with the order of the layers reversed and a method for making the same is provided.

Abstract: Techniques for photocatalytic hydrogen generation are provided. In one aspect, a hydrogen producing cell is provided. The hydrogen producing cell includes an anode electrode; a photocatalytic material adjacent to the anode electrode; a solid electrolyte adjacent to a side of the photocatalytic material opposite the anode electrode; and a cathode electrode adjacent to a side of the solid electrolyte opposite the photocatalytic material. A solar hydrogen producing system including at least one solar concentrating assembly having the hydrogen producing cell, and a method for producing hydrogen using the hydrogen producing cell are also provided.

Abstract: A method for fabricating a photovoltaic device includes forming a polycrystalline absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) over a substrate. The absorber layer is rapid thermal annealed in a sealed chamber having elemental sulfur within the chamber. A sulfur content profile is graded in the absorber layer in accordance with a size of the elemental sulfur and an anneal temperature to provide a graduated bandgap profile for the absorber layer. Additional layers are formed on the absorber layer to complete the photovoltaic device.

Abstract: A method for forming a photovoltaic device includes forming an absorber layer with a granular structure on a conductive layer; conformally depositing an insulating protection layer over the absorber layer to fill in between grains of the absorber layer; and planarizing the protection layer and the absorber layer. A buffer layer is formed on the absorber layer, and a top transparent conductor layer is deposited over the buffer layer.

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: A method for fabricating a photovoltaic device includes forming a polycrystalline absorber layer including Cu—Zn—Sn—S(Se) (CZTSSe) over a substrate. The absorber layer is rapid thermal annealed in a sealed chamber having elemental sulfur within the chamber. A sulfur content profile is graded in the absorber layer in accordance with a size of the elemental sulfur and an anneal temperature to provide a graduated bandgap profile for the absorber layer. Additional layers are formed on the absorber layer to complete the photovoltaic device.

Abstract: A method for texturing silicon includes loading a silicon wafer into a vacuum chamber, heating the silicon wafer and thermal cracking a gas to generate cracked sulfur species. The silicon wafer is exposed to the cracked sulfur species for a time duration in accordance with a texture characteristic needed for a surface of the silicon wafer.

Abstract: Techniques for forming an ohmic back contact for Ag2ZnSn(S,Se)4 photovoltaic devices. In one aspect, a method for forming a photovoltaic device includes the steps of: depositing a refractory electrode material onto a substrate; depositing a contact material onto the refractory electrode material, wherein the contact material includes a transition metal oxide; forming an absorber layer on the contact material, wherein the absorber layer includes Ag, Zn, Sn, and at least one of S and Se; annealing the absorber layer; forming a buffer layer on the absorber layer; and forming a top electrode on the buffer layer. The refractory electrode material may be Mo, W, Pt, Ti, TiN, FTO, and combinations thereof. The transition metal oxide may be TiO2, ZnO, SnO, ZnSnO, Ga2O3, and combinations thereof. A photovoltaic device is also provided.

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: Zinc oxide compositions and methods for controlling zinc oxide particle size for sunscreen applications are provided herein. An example composition includes multiple zinc oxide particles, wherein each of the zinc oxide particles is (i) coated with an optical coating material and (ii) of a size that is below a maximum threshold; and a medium layer within which the zinc oxide particles are suspended, wherein the medium layer comprises a mixture of one or more media, and wherein each of the media has a refractive index below a predetermined threshold.