Abstract: Systems and methods for electrochemical hydrogen looping cells are described. Generating a pH swing can expedite carbon dioxide capture from oceanwater. Many embodiments implement electrochemical hydrogen looping cells that simultaneously produce acid via anodic hydrogen oxidation and base via cathodic hydrogen evolution to generate a pH change.

Abstract: Photoelectrochemical (PEC) technology for the conversion of solar energy into chemicals may require cost-effective photoelectrodes to efficiently and stably drive anodic and/or cathodic half-reactions to complete the overall reactions for storing solar energy in chemical bonds. Apparatus and systems incorporating effectively transparent metal catalysts enable the design and/or implementation of PEC devices for light harvesting. Triple-junction photocathodes with the triangular catalyst grids are provided to improve the efficiency of the photocathodes to generate renewable fuel from sunlight.

Abstract: Systems and methods for catalyzed asymmetric bipolar membranes are described. Catalyzed asymmetric bipolar membranes can sustain desired current densities under low operational voltage for prolonged time periods. Catalyzed asymmetric bipolar membranes can be implemented in electrodialysis cells for various applications such as carbon capture.

Abstract: Provided are an optical modulating device and a system including the optical modulating device. The optical modulating device includes a substrate, and a phase modulator formed on the substrate and including a Fabry-Perot cavity. The Fabry-Perot cavity of the phase modulator includes a first reflective layer, a second reflective layer, and a tunable core formed between the first reflective layer and the second reflective layer, wherein the tunable core is formed of a semiconductor material and is configured to modulate a phase of light corresponding to modulation of a refractive index of the tunable core according to electrical control.

Abstract: Systems and methods for sensing and measuring local pH, pOH, and other protonic species using reversible excited-state photoacids and photobases are described. Various reversible excited-state photoacids and/or photobases are described that through a dynamic sensing mechanism exhibit varied fluorescence or phosphorescence intensity based on local activity of protonic species. Photoacids and photobases can be used in combination with confocal fluorescent microscopy for quantifying local activity of protonic species.

Abstract: The disclosed technology generally relates to characterization of semiconductor structures, and more particularly to optical characterization of high-k dielectric materials. A method includes providing a semiconductor structure comprising a semiconductor and a high-k dielectric layer formed over the semiconductor, wherein the dielectric layer has electron traps formed therein. The method additionally includes at least partially transmitting an incident light having an incident energy through the high-k dielectric layer and at least partially absorbing the incident light in the semiconductor. The method additionally includes measuring a nonlinear optical spectrum resulting from the light having the energy different from the incident energy, the nonlinear optical spectrum having a first region and a second region, wherein the first region changes at a different rate in intensity compared to the second region.

Abstract: Electrically tunable metasurfaces including an array of subwavelength metasurface unit elements are presented. The unit elements include a stacked metal-insulator-metal structure within which an active phase change layer is included. A purely insulator, metal, or coexisting metal-insulator phase of the active layer can be electrically controlled to tune an amplitude and phase response of the metasurfaces. In combination with the subwavelengths dimensions of the unit elements, the phase and amplitude response can be controlled in a range from optical wavelengths to millimeter wavelength of incident light. Electrical control of the unit elements can be provided via resistive heating produced by flow of current though a top metal layer of the unit elements. Alternatively, electrical control of the unit elements can be provided via electrical field effect produced by applying a voltage differential between the top and bottom metal layers of the unit elements.

Abstract: Provided is a metaoptic configured to modulate incident light in a wavelength band, the metaoptic including a plurality of meta units respectively including a first semiconductor layer, an active layer provided on the first semiconductor layer, the active layer having a multiple quantum well structure and a refractive index variable based on a voltage applied thereto, and a second semiconductor layer provided on the active layer and doped with a polarity opposite to a polarity of the first semiconductor layer, wherein at least one of the plurality of meta units includes a plurality of first elements having a cylindrical shape and periodically provided spaced apart from each other in a first direction, and a plurality of second elements connecting the plurality of first elements to each other, and wherein the plurality of meta units are provided in a second direction that is perpendicular to the first direction.

Abstract: Multi-functional coilable thin-walled structures that can be implemented within space-based satellite modules, and methods for their manufacture are provided. Multi-functional coilable thin-walled structures are comprised of at least one longeron that is capable of rolling and collapsing upon itself. In some embodiments, the coilable thin-walled longeron is a flange longeron. The flange longeron contains at least two major regions: a web and a plurality of flanges. The web region comprises portions of flanges that are bonded to one another. The plurality of flanges separate from one another on the same end of the web region. The plurality of flanges are similar in thickness and shape.

Abstract: Systems and methods of gas-liquid contactors for direct ocean capture and/or direct air capture are described.

Abstract: A membrane for water collection may include a sheet having a top surface and a bottom surface, and a plurality of conical structures disposed on the top surface of the sheet, the conical structures comprising a hydrogel material. Each conical structure of the plurality of conical structures may have a height of 1 mm to 50 mm, wherein height is measured from the top surface of the sheet to an apex of a conical structure. Each conical structure of the plurality of conical structures may have an apex angle of 10 to 60 degrees.

Abstract: Systems and methods of three-terminal tandem solar cells are described. Three-terminal metal electrodes can be formed to contact subcells of the tandem solar cell. The three-terminal tandem cell can improve the device efficiency to at least 30%.

Abstract: Provided are an optical modulating device and a system including the optical modulating device. The optical modulating device includes a substrate, and a phase modulator formed on the substrate and including a Fabry-Perot cavity. The Fabry-Perot cavity of the phase modulator includes a first reflective layer, a second reflective layer, and a tunable core formed between the first reflective layer and the second reflective layer, wherein the tunable core is formed of a semiconductor material and is configured to modulate a phase of light corresponding to modulation of a refractive index of the tunable core according to electrical control.

Abstract: Provided are an optical modulating device and a system including the optical modulating device. The optical modulating device includes a substrate, and a phase modulator formed on the substrate and including a Fabry-Perot cavity. The Fabry-Perot cavity of the phase modulator includes a first reflective layer, a second reflective layer, and a tunable core formed between the first reflective layer and the second reflective layer, wherein the tunable core is formed of a semiconductor material and is configured to modulate a phase of light corresponding to modulation of a refractive index of the tunable core according to electrical control.

Abstract: Resonant optical cavities incorporating black phosphorus to enable electrically tunable control of light are disclosed. Methods and devices are described that use black phosphorus as an electrically tunable optical material to control phase, amplitude and/or polarization of light from visible to mid-infrared wavelengths. The operating wavelength of the optical cavities depends on the thickness of the embedded black phosphorous. Tunable control of light is performed by adjusting the doping level of black phosphorous.

Abstract: A light modulating device for modulating incident light in a given wavelength band is provided. The light modulating device may include: a first semiconductor layer; an active layer provided on the first semiconductor layer and having a multiple quantum well structure and a refractive index that is variable according to an electric field applied thereto, and a second semiconductor layer provided on the active layer and including a grating pattern in which a plurality of gratings extending in a first direction are repeatedly arranged in a second direction perpendicular to the first direction. The light modulating device may have high modulation efficiency owing to guided mode resonance by the grating pattern.

Abstract: Photovoltaics configured to be manufactured without epitaxial processes and methods for such manufacture are provided. Methods utilize bulk semiconducting crystal substrates, such as, for example, GaAs and InP such that epitaxy processes are not required. Nanowire etch and exfoliation processes are used allowing the manufacture of large numbers of photovoltaic cells per substrate wafer (e.g., greater than 100). Photovoltaic cells incorporate electron and hole selective contacts such that epitaxial heterojunctions are avoided during manufacture.

Abstract: A space-based solar power station, a power generating satellite module and/or a method for collecting solar radiation and transmitting power generated using electrical current produced therefrom is provided. Each solar power station includes a plurality of satellite modules. The plurality of satellite modules each include a plurality of modular power generation tiles including a photovoltaic solar radiation collector, a power transmitter and associated control electronics. Numerous embodiments relate to efficient power generation tiles. In one embodiment, an efficient power generation tile includes: at least one photovoltaic material; and at least one concentrator that redirects incident solar radiation towards a photovoltaic material such that the photovoltaic material experiences a greater solar flux relative to the case where the photovoltaic material experiences unaltered solar radiation.

Abstract: Disclosed are electrochemical systems that include an electrodialyzer and a vapor-fed CO2 reduction (CO2R) cell to capture and convert CO2 from ocean water. The electrodialyzer includes a stack of bipolar membrane electrodialysis (BPMED) cells between end electrodes. The electrodialzyer incorporates monovalent cation exchange membranes (M-CEMs) that prevent the transfer of multivalent cations between adjacent cell compartments, allowing continuous recirculation of electrolytes and solutions, and thus providing a safer and more scaling-free electrodialysis system. In some embodiments, the electrodialyzer may be configured to replace the water-splitting reaction at end electrodes with one-electron, reversible redox couples in solution at the electrodes. As a result, in the entire electrodialyzer stack, there is no bond-making, bond-breaking reactions and there is no gas generation, which significantly simplifies the cell design and improves operational safety.

Abstract: Systems and methods of three-terminal tandem solar cells are described. Three-terminal metal electrodes can be formed to contact subcells of the tandem solar cell. The three-terminal tandem cell can improve the device efficiency to at least 30%.