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Abstract The design and development of solar‐blind photodetectors utilizing ultrawide bandgap semiconductors have garnered significant attention due to their extensive utility in specialty commercial sectors. Solar‐blind photodetectors that display excellent photosensitivity, fast response time and are produced using cost‐effective fabrication steps will fulfill the performance demands in relevant applications. Herein, highly textured Sn‐doped Ga₂O₃thin film metal‐semiconductor‐metal type deep‐UV photodetectors using a commercially scalable magnetron sputtering method are reported. Commercially achievable growth and fabrication steps are intentionally chosen to demonstrate an economically viable photodetection workflow without compromising the device's performance. In‐depth structural, morphological, chemical, and optical characterization are reported to optimize the configuration for further device fabrication and testing. Under transient triggering circumstances, a fast response time of ≈500 ms is reported, accompanied by a responsivity of ≈60.5 A W⁻¹. The detectivity, external quantum efficiency, and photo‐to‐dark current ratio values are reported as 1.6 × 10¹³Jones, 2.8 × 10⁴%, and 17.4, respectively. The overall device performance and cost‐effective fabrication process for solar‐blind UV photodetection using Sn‐doped Ga₂O₃is promising. The approach holds promise for significant implications toward the development of electronics capable of functioning in extreme environments and exhibits substantial potential for enhancing low‐cost UV photodetector technology. 

Supercapacitors and batteries are essential for sustainable energy development. However, the bottleneck is the associated high cost, which limits bulk use of batteries and supercapacitors. In this context, realizing that the cost of energy‐storage device mainly depends on materials, synthesis processes/procedures, and device fabrication, an effort is made to rationally design and develop novel low‐cost electrode materials with enhanced electrochemical performance in asymmetric supercapacitors. Herein, surface functionalization approach is adopted to design low‐cost 3D mesoporous and nanostructured nickel–nickel oxide electrode materials using facile synthesis for application in supercapacitors. It is demonstrated that the 3D mesoporous Ni provides the high surface area and enhanced ionic conductivity, while germanium functionalization improves the electrical conductivity and reduces the charge‐transfer resistance of NiO. Surface functionalization with Ge demonstrates the significant improvement in specific capacitance of NiO. The asymmetric supercapacitor using these Ge‐functionalized NiO–Ni electrodes provides a specific capacitance of 304 Fg⁻¹(94 mF cm⁻²), energy density of 23.8 Wh kg⁻¹(7.35 μWh cm⁻²), and power density of 6.8 kW kg⁻¹(2.1 mW cm⁻²) with excellent cyclic stability of 92% after 10 000 cycles. To validate their practical applications, powering the digital watch using the asymmetric supercapacitors in laboratory conditions is demonstrated. 

Despite extensive research and technology to reduce the atmospheric emission of Pb from burning coal for power generation, minimal attention has been paid to Pb associated with coal ash disposal in the environment. This study investigates the isotopic signatures and output rates of Pb in fly ash disposal in China, India, and the United States. Pairwise comparison between feed coal and fly ash samples collected from coal-fired power plants from each country shows that the Pb isotope composition of fly ash largely resembles that of feed coal, and its isotopic distinction allows for tracing the release of Pb from coal fly ash into the environment. Between 2000 and 2020, approx. 236, 56, and 46 Gg Pb from fly ash have been disposed in China, India, and the U.S., respectively, posing a significant environmental burden. A Bayesian Pb isotope mixing model shows that during the past 40 to 70 years, coal fly ash has contributed significantly higher Pb (∼26%) than leaded gasoline (∼7%) to Pb accumulation in the sediments of five freshwater lakes in North Carolina, U.S.A. This implies that the release of disposed coal fly ash Pb at local and regional scales can outweigh that of other anthropogenic Pb sources.