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III–V‐based multijunction solar cells have become the leading power generation technology for space applications due to their high power conversion efficiency and reliable performance in extraterrestrial environments. Thinning down the absorber layers of multijunction solar cells can considerably reduce the production cost and improve their radiation hardness. Recent advances in ultrathin GaAs single‐junction solar cells suggest the development of light‐trapping nanostructures to increase light absorption in optically thin layers within III–V‐based multijunction solar cells. Herein, a novel and highly scalable nanosphere lithography‐assisted chemical etching method to fabricate light‐trapping nanostructures in InGaP/GaAs dual‐junction solar cells is studied. Numerical models show that integrating the nanostructured Al₂O₃/Ag rear mirror significantly enhances the broadband absorption within the GaAs bottom cell. Results demonstrate that the light‐trapping nanostructures effectively increase the short‐circuit current density in GaAs bottom cells from 14.04 to 15.06 mA cm⁻². The simulated nanostructured InGaP/GaAs dual‐junction structure shows improved current matching between the GaAs bottom cell and the InGaP top cell, resulting in 1.12x higher power conversion efficiency. These findings highlight the potential of light‐trapping nanostructures to improve the performance of III‐V‐based multijunction photovoltaic systems, particularly for high‐efficiency applications in space. 

Metal–insulator–semiconductor/MIS-based photoelectrochemical (PEC) water splitting provides a scalable and integrated platform to harness renewable solar energy for green hydrogen production. 

Abstract An extremely rapid process for self‐assembling well‐ordered, nano, and microparticle monolayers via a novel aerosolized method is presented. The novel technique can reach monolayer self‐assembly rates as high as 268 cm²min⁻¹from a single aerosolizing source and methods to reach faster monolayer self‐assembly rates are outlined. A new physical mechanism describing the self‐assembly process is presented and new insights enabling high‐efficiency nanoparticle monolayer self‐assembly are developed. In addition, well‐ordered monolayer arrays from particles of various sizes, surface functionality, and materials are fabricated. This new technique enables a 93× increase in monolayer self‐assembly rates compared to the current state of the art and has the potential to provide an extremely low‐cost option for submicron nanomanufacturing. 

Abstract Fabrication of micro- and nanoscale electronic components has become increasingly demanding due to device and interconnect scaling combined with advanced packaging and assembly for electronic, aerospace, and medical applications. Recent advances in additive manufacturing have made it possible to fabricate microscale, 3D interconnect structures but heat transfer during the fabrication process is one of the most important phenomena influencing the reliable manufacturing of these interconnect structures. In this study, optical absorption and scattering by three-dimensional (3D) nanoparticle packings are investigated to gain insight into micro/nano heat transport within the nanoparticles. Because drying of colloidal solutions creates different configurations of nanoparticles, the plasmonic coupling in three different copper nanoparticle packing configurations was investigated: simple cubic (SC), face-centered cubic (FCC), and hexagonal close packing (HCP). Single-scatter albedo (ω) was analyzed as a function of nanoparticle size, packing density, and configuration to assess effect for thermo-optical properties and plasmonic coupling of the Cu nanoparticles within the nanoparticle packings. This analysis provides insight into plasmonically enhanced absorption in copper nanoparticle particles and its consequences for laser heating of nanoparticle assemblies. 

Abstract Metal-insulator-semiconductor (MIS) structures are widely used in Si-based solar water-splitting photoelectrodes to protect the Si layer from corrosion. Typically, there is a tradeoff between efficiency and stability when optimizing insulator thickness. Moreover, lithographic patterning is often required for fabricating MIS photoelectrodes. In this study, we demonstrate improved Si-based MIS photoanodes with thick insulating layers fabricated using thin-film reactions to create localized conduction paths through the insulator and electrodeposition to form metal catalyst islands. These fabrication approaches are low-cost and highly scalable, and yield MIS photoanodes with low onset potential, high saturation current density, and excellent stability. By combining this approach with a p⁺n-Si buried junction, further improved oxygen evolution reaction (OER) performance is achieved with an onset potential of 0.7 V versus reversible hydrogen electrode (RHE) and saturation current density of 32 mA/cm²under simulated AM1.5G illumination. Moreover, in stability testing in 1 M KOH aqueous solution, a constant photocurrent density of ~22 mA/cm²is maintained at 1.3 V versus RHE for 7 days.