We present a bias-free photoconductive emitter that uses an array of nanoantennas on an InGaAs layer with a linearly graded Indium composition. The graded InGaAs structure creates a built-in electric field that extends through the entire photoconductive active region, enabling the efficient drift of the photo-generated electrons to the nanoantennas. The nanoantenna geometry is chosen so that surface plasmon waves are excited in response to a 1550 nm optical pump to maximize photo-generated carrier concentration near the nanoantennas, where the built-in electric field strength is maximized. With the combination of the plasmonic enhancement and built-in electric field, high-power terahertz pulses are generated without using any external bias voltage. We demonstrate the generation of terahertz pulses with 860 µW average power at an average optical pump power of 900 mW, exhibiting the highest radiation power compared to previously demonstrated telecommunication-compatible terahertz pulse emitters.
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http://dx.doi.org/10.1364/OE.447733 | DOI Listing |
Talanta
January 2025
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, PR China. Electronic address:
Formaldehyde (HCHO) is a harmful volatile organic pollutant, which is commonly found in interior decoration and furniture products. Therefore, it is necessary to develop a gas sensor that can quickly and accurately detect formaldehyde for human health and environmental protection. In order to achieve this goal, in this work, SnS/SnO heterostructure was synthesized by in-situ sulfurization process on the basis of SnO nanospheres, and its formaldehyde sensing performance was studied.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Key Laboratory of Advanced Catalytic Materials and Technology, Advanced Catalysis and Green Manufacturing Collaborative Innovation Center, Changzhou University, Changzhou, Jiangsu Province 213164, China. Electronic address:
Despite the advancement of the Pt-catalyzed hydrogen evolution reaction (HER) through oxophilic metal-hydroxide surface hybridization, its stability in acidic solutions remains unsatisfactory. This is primarily due to excessive aggregation of active hydrogen, which hinders subsequent hydrogen desorption, coupled with the poor operational stability of metal hydroxides. In this study, we have designed Pt nanoparticles-modified NiFeCoCuCr high-entropy layered double hydroxides (Pt/HE-LDH) that exhibit exceptional catalytic activity toward HER in acidic electrolytes.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Physics, Pohang University of Science and Technology, 77, Cheongam-ro, Nam-gu, Pohang, 37673, Korea (the Republic of).
Janus materials, a novel class of materials with two faces of different chemical compositions and electronic polarities, offer significant potential for various applications with catalytic reactions, chemical sensing, and optical or electronic responses. A key aspect for such functionalities is face-dependent electronic bipolarity, which is usually limited by the chemical distinction of terminated surfaces and has not been exploited in the semiconducting regime. Here, it is showed that a Janus and Kagome van der Waals (vdW) material NbTeI has ferroelectric-like coherent stacking of the Janus layers and hosts strong electronic bipolar states in the semiconducting regime.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemistry, Fudan University, Shanghai 200433, China.
Vanadium-based oxides have garnered significant attention for aqueous zinc batteries (AZBs), whereas sluggish Zn diffusion and structural collapse remain major challenges in achieving high-performance cathodes. Herein, different structures of iron-vanadium oxides were fabricated by modulating the amount of vanadium content. It is found that the porous Mott-Schottky heterojunction composed of FeVO and FeVO mixed phase was used to construct a self-generated FeVO-5 structure, which could lower the diffusion barrier and improve the electron transport derived from the formed built-in electric field at the interface, showing faster reaction kinetics and improved capacity compared with the singe-phase FeVO-1.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-Gu, Seoul 04763, Republic of Korea.
In this research, S-scheme heterojunction photocatalysts are prepared through the hybridization of nitrogen-rich g-CN with TiO (coded as TCN-(): as the weight ratio of TiO:g-CN). The photocatalytic potential of TCN-() is evaluated against benzene (1-5 ppm) across varying humidity levels using a dynamic flow packed-bed photocatalytic reactor. Among the prepared composites, TCN-(10) exhibits the highest synergy between g-CN and TiO at "" ratio of 10%, showing superior best benzene degradation performance (e.
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