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: 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: 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: Oxide electron selective contacts for perovskite solar cells are provided. In one aspect, a method of forming a perovskite solar cell is provided. The method includes the steps of: depositing a layer of a hole transporting material on a substrate; forming a perovskite absorber on the hole transporting material; depositing an oxide electron transporting material on the perovskite absorber; and forming a top electrode on the oxide electron transporting material. Perovskite solar cells and tandem photovoltaic devices 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: 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 multi-junction photovoltaic device includes a silicon substrate and a dielectric layer formed on the silicon substrate. A germanium layer is formed on the dielectric layer. The germanium includes a crystalline structure that is substantially similar to the crystalline structure of the silicon substrate. A first photovoltaic sub-cell includes a first plurality of doped semiconductor layers formed on the germanium layer. At least a second photovoltaic sub-cell includes a second plurality of doped semiconductor layers formed on the first photovoltaic sub-cell that is on the germanium layer that is on the dielectric layer.

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: 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 providing high-capacity, re-workable connections in concentrated photovoltaic devices are provided. In one aspect, a lead frame package for a photovoltaic device is provided that includes a beam shield; and one or more lead frame connectors affixed to the beam shield, wherein the lead frame connectors are configured to provide connection to the photovoltaic device when the photovoltaic device is assembled to the lead frame package. A photovoltaic apparatus is also provided that includes a lead frame package assembled to a photovoltaic device. The lead frame package includes a beam shield and one or more lead frame connectors affixed to the beam shield, wherein the lead frame connectors are configured to provide connection to the photovoltaic device.

Abstract: A method of tagging an article is disclosed. Data that identifies the article is encoded into at least one stress value. A stress region having a stress that corresponds to the at least one stress value is created in a surface of the article to the tag the article. The at least one stress value is read by a measurement device to read the data and identify the article.

Abstract: A method of tagging an article is disclosed. Data that identifies the article is encoded into at least one stress value. A stress region having a stress that corresponds to the at least one stress value is created in a surface of the article to the tag the article. The at least one stress value is read by a measurement device to read the data and identify the article.

Abstract: Techniques for epitaxial growth of CZT(S,Se) materials on Si are provided. In one aspect, a method of forming an epitaxial kesterite material is provided which includes the steps of: selecting a Si substrate based on a crystallographic orientation of the Si substrate; forming an epitaxial oxide interlayer on the Si substrate to enhance wettability of the epitaxial kesterite material on the Si substrate, wherein the epitaxial oxide interlayer is formed from a material that is lattice-matched to Si; and forming the epitaxial kesterite material on a side of the epitaxial oxide interlayer opposite the Si substrate, wherein the epitaxial kesterite material includes Cu, Zn, Sn, and at least one of S and Se, and wherein a crystallographic orientation of the epitaxial kesterite material is based on the crystallographic orientation of the Si substrate. A method of forming an epitaxial kesterite-based photovoltaic device and an epitaxial kesterite-based device 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: Techniques for epitaxial growth of CZT(S,Se) materials on Si are provided. In one aspect, a method of forming an epitaxial kesterite material is provided which includes the steps of: selecting a Si substrate based on a crystallographic orientation of the Si substrate; forming an epitaxial oxide interlayer on the Si substrate to enhance wettability of the epitaxial kesterite material on the Si substrate, wherein the epitaxial oxide interlayer is formed from a material that is lattice-matched to Si; and forming the epitaxial kesterite material on a side of the epitaxial oxide interlayer opposite the Si substrate, wherein the epitaxial kesterite material includes Cu, Zn, Sn, and at least one of S and Se, and wherein a crystallographic orientation of the epitaxial kesterite material is based on the crystallographic orientation of the Si substrate. A method of forming an epitaxial kesterite-based photovoltaic device and an epitaxial kesterite-based device are also 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: 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: Tandem Kesterite-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 bottom cell having a first absorber layer comprising copper, zinc, tin, and at least one of sulfur and selenium and a top cell connected in series with the bottom cell, the top cell having a second absorber layer comprising a perovskite material. A method of forming a tandem photovoltaic device is also provided.

Abstract: A method, an apparatus and an article of manufacture for forecasting a meteorological parameter. The method includes analyzing geographically distributed sensor network data to assess spatial and temporal variation of a meteorological parameter in real-time, correlating at least two portions of data from the sensor network to identify a temporal and spatial evolution of the meteorological parameter, and forecasting the meteorological parameter based on the temporal and spatial evolution of the meteorological parameter.

Abstract: A method, an apparatus and an article of manufacture for forecasting a meteorological parameter. The method includes analyzing geographically distributed sensor network data to assess spatial and temporal variation of a meteorological parameter in real-time, correlating at least two portions of data from the sensor network to identify a temporal and spatial evolution of the meteorological parameter, and forecasting the meteorological parameter based on the temporal and spatial evolution of the meteorological parameter.