Abstract: Provided herein are resistive switching devices comprising a nanocomposite, an inert electrode and an active electrode. Also provided are methods for preparing and using the disclosed resistive switching devices.

Abstract: Techniques for hybrid solar thermal and photovoltaic energy collection are provided. In one aspect, a photovoltaic concentrating thermal collector (PVCTC) includes: a thermal absorber collector; and bent solar panels forming a parabolic shaped trough reflector partially surrounding the thermal absorber collector so as to reflect incident light onto the thermal absorber collector. A PVCTC system including an array of PVCTC units and a method for hybrid electrical and thermal energy production are also provided.

Abstract: Techniques for mechanically stabilizing metallic nanowire meshes using encapsulation are provided. In one aspect, a method for forming a mechanically-stabilized metallic nanowire mesh is provided which includes the steps of: forming the metallic nanowire mesh on a substrate; and coating the metallic nanowire mesh with a metal oxide that encapsulates the metallic nanowire mesh to mechanically-stabilize the metallic nanowire mesh which permits the metallic nanowire mesh to remain conductive at temperatures greater than or equal to about 600° C. A mechanically-stabilized metallic nanowire mesh is also provided.

Abstract: Techniques for hybrid solar thermal and photovoltaic energy collection are provided. In one aspect, a photovoltaic concentrating thermal collector (PVCTC) includes: a thermal absorber collector; and bent solar panels forming a parabolic shaped trough reflector partially surrounding the thermal absorber collector so as to reflect incident light onto the thermal absorber collector. A PVCTC system including an array of PVCTC units and a method for hybrid electrical and thermal energy production are also provided.

Abstract: Vacuum annealing-based techniques for forming perovskite materials are provided. In one aspect, a method of forming a perovskite material is provided. The method includes the steps of: depositing a metal halide layer on a sample substrate; and vacuum annealing the metal halide layer and methylammonium halide under conditions sufficient to form methylammonium halide vapor which reacts with the metal halide layer and forms the perovskite material on the sample substrate. A perovskite-based photovoltaic device and method of formation thereof are also provided.

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: Techniques for mechanically stabilizing metallic nanowire meshes using encapsulation are provided. In one aspect, a method for forming a mechanically-stabilized metallic nanowire mesh is provided which includes the steps of: forming the metallic nanowire mesh on a substrate; and coating the metallic nanowire mesh with a metal oxide that encapsulates the metallic nanowire mesh to mechanically-stabilize the metallic nanowire mesh which permits the metallic nanowire mesh to remain conductive at temperatures greater than or equal to about 600° C. A mechanically-stabilized metallic nanowire mesh is also provided.

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: Vacuum annealing-based techniques for forming perovskite materials are provided. In one aspect, a method of forming a perovskite material is provided. The method includes the steps of: depositing a metal halide layer on a sample substrate; and vacuum annealing the metal halide layer and methylammonium halide under conditions sufficient to form methylammonium halide vapor which reacts with the metal halide layer and forms the perovskite material on the sample substrate. A perovskite-based photovoltaic device and method of formation thereof are also provided.

Abstract: Monolithic tandem chalcopyrite-perovskite photovoltaic devices and techniques for formation thereof are provided. In one aspect, a tandem photovoltaic device is provided. The tandem photovoltaic device includes a substrate; a bottom solar cell on the substrate, the bottom solar cell having a first absorber layer that includes a chalcopyrite material; and a top solar cell monolithically integrated with the bottom solar cell, the top solar cell having a second absorber layer that includes a perovskite material. A monolithic tandem photovoltaic device and method of formation thereof are also provided.

Abstract: Low power combustible gas sensors using a thermocouple design are provided. In one aspect, a combustible gas sensor includes: at least one first electrode; at least one second electrode formed from a dissimilar material from the first electrode; and a catalytic material at an active reaction junction between the first electrode and the second electrode, wherein the active reaction junction between the first electrode and the second electrode forms a thermocouple. A sensing device is including, e.g., multiple sensors, and a method for sensing combustible gas using the present sensors are also provided.

Abstract: The disclosure relates to a method for forming a low refractive index layer on a substrate. The method generally includes (a) applying a block copolymer layer on a substrate, the block copolymer including a polar polymeric block and a non-polar polymeric block; (b) swelling the block copolymer layer with a solvent to increase the block copolymer layer thickness; (c) depositing a metal oxide or metalloid oxide layer on polar polymeric blocks of the block copolymer layer; and (d) removing the block copolymer layer from the substrate, thereby forming a porous metal oxide or metalloid oxide layer on the substrate.

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: 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: 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: Techniques for hybrid solar thermal and photovoltaic energy collection are provided. In one aspect, a photovoltaic concentrating thermal collector (PVCTC) includes: a thermal absorber collector; and bent solar panels forming a parabolic shaped trough reflector partially surrounding the thermal absorber collector so as to reflect incident light onto the thermal absorber collector. A PVCTC system including an array of PVCTC units and a method for hybrid electrical and thermal energy production are also provided.

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: 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 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.