Recent investigations of semiconductor nanowires have provided strong evidence for enhanced light absorption, which has been attributed to nanowire structures functioning as optical cavities. Precise synthetic control of nanowire parameters including chemical composition and morphology has also led to dramatic modulation of absorption properties. Here we report finite-difference time-domain (FDTD) simulations for silicon (Si) nanowire cavities to elucidate the key factors that determine enhanced light absorption. The FDTD simulations revealed that a crystalline Si nanowire with an embedded 20-nm-thick amorphous Si shell yields 40% enhancement of absorption as compared to a homogeneous crystalline Si nanowire, under air-mass 1.5 global solar spectrum for wavelengths between 280 and 1000 nm. Such a large enhancement in absorption results from localization of several resonant modes within the amorphous Si shell. A nanowire with a rectangular cross section exhibited enhanced absorption at specific wavelengths with respect to a hexagonal nanowire. The pronounced absorption peaks were assigned to resonant modes with a high symmetry that red-shifted with increasing size of the rectangular nanowire. We extended our studies to investigate the optical properties of single- and multilayer arrays of these horizontally oriented nanowire building blocks. The absorption efficiency of a nanowire stack increases with the number of nanowire layers and was found to be greater than that of a bulk structure or even a single nanowire of equivalent thickness. Lastly, we found that a single-layer nanowire array preserves the structured absorption spectrum of a single nanowire and ascribed this result to a diffraction effect of the periodic nanowire array. The results from these provide insight into the design of nanowire optical cavities with tunable and enhanced light absorption and thus, could help enable the development of ultrathin solar cells and other nanoscale optoelectronic devices.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/nn5003776 | DOI Listing |
Nanotechnology
January 2025
Xi'an Jiaotong University, xian ning west road 28#, xi'an, Xi'an, None Selected, 710049, CHINA.
Accurate and rapid diagnosis of traumatic brain injury (TBI) is essential for high-quality medical services. Nonetheless, the current diagnostic platform still has challenges in rapidly and accurately analysing clinical samples. Here, we prepared a highly stable, repeatable and sensitive gold-plated silver core-shell nanowire (Ag@AuNWs) for surface-enhanced Raman spectroscopy (SERS) metabolic fingerprint diagnosis of TBI.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Eco-chemical Engineering, International S&T Cooperation Foundation of Eco-chemical Engineering and Green Manufacture, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P. R. China.
Crafting anisotropically epitaxial p-n heterostructures with Z-scheme charge transmission is a promising avenue toward excellent photocatalytic efficiency, yet the large lattice mismatch and diverse crystal growth habits between components have often arisen as a big challenge to this goal. Here, anisotropically epitaxial p-n heterostructures with 19.8% lattice mismatch are obtained via a dynamics-mediated seeded growth tactic under reaction temperature as low as 60 °C.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Faculty of Textile Technologies and Design, Istanbul Technical University, Istanbul, Turkey. Electronic address:
Wound care presents an imposed financial burden for healthcare organizations, prompting the need for novel and cost-efficient dressings. In this study, we address this challenge by introducing a novel approach to fabricate antibacterial alginate-based fibrous materials using a combination of wet spinning and the wet-laying method, which offer advantages including structural and functional properties such as breathability, nontoxicity, biocompatibility, and cost-effectiveness. The wet spinning method was employed to develop porous and non-porous Ca-alginate fibers with diameters of 100 ± 4.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, 518057, China.
Over-oxidation of surface ruthenium active sites of RuO-based electrocatalysts leads to the formation of soluble high-valent Ru species and subsequent structural collapse of electrocatalysts, which results in their low stability for the acidic oxygen evolution reaction (OER). Herein, a binary RuO/NbO electrocatalyst with abundant and intimate interfaces has been rationally designed and synthesized to enhance its OER activity in acidic electrolyte, delivering a low overpotential of 179 mV at 10 mA cm, a small Tafel slope of 73 mV dec, and a stabilized catalytic durability over a period of 750 h. Extensive experiments have demonstrated that the spillover of active oxygen intermediates from RuO to NbO and the subsequent participation of lattice oxygen of NbO instead of RuO for the acidic OER suppressed the over-oxidation of surface ruthenium species and thereby improved the catalytic stability of the binary electrocatalysts.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Computer Science, Faculty of Sciences and Humanities Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia.
Impedance-based biosensing has emerged as a critical technology for high-sensitivity biomolecular detection, yet traditional approaches often rely on bulky, costly impedance analyzers, limiting their portability and usability in point-of-care applications. Addressing these limitations, this paper proposes an advanced biosensing system integrating a Silicon Nanowire Field-Effect Transistor (SiNW-FET) biosensor with a high-gain amplification circuit and a 1D Convolutional Neural Network (CNN) implemented on FPGA hardware. This attempt combines SiNW-FET biosensing technology with FPGA-implemented deep learning noise reduction, creating a compact system capable of real-time viral detection with minimal computational latency.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!