Abstract: A multi-junction artificial photosynthetic unit includes an active element with a plurality of semiconducting layers, with metal layers deposited between the semiconductor layers appropriately forming Schottky barrier junctions or ohmic junctions with a surface of an adjacent semiconductor layer. The active element is formed within a protective structure formed of porous aluminum oxide. Successive layers of the active element can be formed within the protective structure, and additional layers and junctions can be added until desired photovoltages are achieved. A photoreactor for the production of fuels and chemicals driven by solar-powered redox reactions includes a bag reactor filled with a feedstock solution. A plurality of multi-junction photosynthetic units are placed in the feedstock solution to drive the redox reactions and produce the desired fuels and chemicals.

Abstract: A photoelectrosynthetically active heterostructure (PAH) is manufactured by forming or providing cavities in an electrically insulating material; forming or providing an electrically conductive layer on a side of the electrically insulating material; depositing an electrocatalyst cathode layer in the cavities; depositing one or more layers of light-absorbing semiconductor material in the cavities; depositing an electrocatalyst anode layer in the cavities; removing the layer of electrically conductive metal; and forming a hydrogen permeable layer over the electrocatalyst cathode layer. The one or more layers of light-absorbing semiconductor material can form a p-n junction or Schottky junction. The PAH can be used in photoelectrosynthetic processes to produce desired products, such as reduction product (e.g., methane gas, methanol, or carbon monoxide) from carbon dioxide and liquid waste streams.

Abstract: A two-step process, consisting of a photoelectrosynthetic process combined with a thermochemical process, is configured to produce a reduction product (e.g., methane gas, methanol, or carbon monoxide) from carbon dioxide and liquid waste streams. In a first step, photoelectrosynthetically active heterostructures (PAHs) and sunlight are used to drive oxidation/reduction reactions in which one primary product is hydrogen gas. In the second step, hydrogen generated in the first step is thermally catalytically reacted with carbon dioxide to form a reduction product from carbon dioxide (e.g., CO, formaldehyde, methane, or methanol). Synthesis gas (CO and H2) can be further reacted to form alkanes. The methods and systems may employ PAHs known in the art or improved PAHs having lower costs, improved stability, solar energy conversion efficiency, and/or other desired attributes as disclosed herein.

Abstract: A multi-junction artificial photosynthetic unit includes an active element with a plurality of semiconducting layers, with metal layers deposited between the semiconductor layers appropriately forming Schottky barrier junctions or ohmic junctions with a surface of an adjacent semiconductor layer. The active element is formed within a protective structure formed of porous aluminum oxide. Successive layers of the active element can be formed within the protective structure, and additional layers and junctions can be added until desired photovoltages are achieved. A photoreactor for the production of fuels and chemicals driven by solar-powered redox reactions includes a bag reactor filled with a feedstock solution. A plurality of multi-junction photosynthetic units are placed in the feedstock solution to drive the redox reactions and produce the desired fuels and chemicals.

Abstract: A photonics-based planar solar concentrator designed for collecting and guiding insolate radiation from one side to solar cells for energy conversion on another side is described. The planar solar concentrator consists of two sections. The top section is a matrix of micro-size wide angle solar concentrators. The bottom section is a planar lightwave circuit, which may be multi-layered. Planar lightwave circuits are used within a relatively thin cross-sectional thickness to guide light from micro-concentrators to output apertures on the opposite surface, such that solar cells can be located directly underneath the concentrator. The planar concentrator can deliver multiple times the normal sunlight intensity to standard silicon solar cells, thereby decreasing the number of cells required in a typical solar module. This planar solar concentrator is designed for use as the top optical layer of a standard flat panel solar module.