Currently the AlGaN-based ultraviolet (UV) solid-state lighting research suffers from numerous challenges. In particular, low internal quantum efficiency, low extraction efficiency, inefficient doping, large polarization fields, and high dislocation density epitaxy constitute bottlenecks in realizing high power devices. Despite the clear advantage of quantum-confinement nanostructure, it has not been widely utilized in AlGaN-based nanowires. Here we utilize the self-assembled nanowires (NWs) with embedding quantum-disks (Qdisks) to mitigate these issues, and achieve UV emission of 337 nm at 32 A/cm (80 mA in 0.5 × 0.5 mm device), a turn-on voltage of ~5.5 V and droop-free behavior up to 120 A/cm of injection current. The device was grown on a titanium-coated n-type silicon substrate, to improve current injection and heat dissipation. A narrow linewidth of 11.7 nm in the electroluminescence spectrum and a strong wavefunctions overlap factor of 42% confirm strong quantum confinement within uniformly formed AlGaN/AlGaN Qdisks, verified using transmission electron microscopy (TEM). The nitride-based UV nanowires light-emitting diodes (NWs-LEDs) grown on low cost and scalable metal/silicon template substrate, offers a scalable, environment friendly and low cost solution for numerous applications, such as solid-state lighting, spectroscopy, medical science and security.
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http://dx.doi.org/10.1364/OE.25.001381 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Henan University of Technology, School of Chemistry and Chemical Engineering, CHINA.
Developing of molecular crystalline materials with light-induced multiple dynamic deformation in space dimension and photochromism on time scales has attracted much attention for its potential applications in actuators, sensoring and information storage. Nevertheless, organic crystals capable of both photoinduced dynamic effects and static color change are rare, particularly for multi-component cocrystals system. In this study, we first report the construction of charge transfer co-crystals allows their light-induced solid-to-liquid transition and photochromic behaviors to be controlled by trans-stilbene (TSB) as an electron donor and 3,4,5,6-Tetrafluorophthalonitrile (TFP) as an electron acceptor.
View Article and Find Full Text PDFNat Commun
January 2025
Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, P. R. China.
The unsatisfactory ionic conductivity of solid polymer electrolytes hinders their practical use as substitutes for liquid electrolytes to address safety concerns. Although various plasticizers have been introduced to improve lithium-ion conduction kinetics, the lack of microenvironment understanding impedes the rational design of high-performance polymer electrolytes. Here, we design a class of Hofmann complexes that offer continuous two-dimensional lithium-ion conduction channels with functional ligands, creating highly conductive electrolytes.
View Article and Find Full Text PDFLasers Med Sci
January 2025
University of Zurich, Zurich, Switzerland.
The aim of this study was to compare the effectiveness of different types of low level laser treatment (LLLT) in reducing pain levels, changing oxygen saturation and bite force in patients with myofacial pain syndrome (MPS). 45 patients were randomly assigned to three groups: Group 1 (GRR laser, n = 15) received LLLT with Gallium-Aluminium-Arsenide (GaAlAs) diode laser with a wavelength of 904 nm and red laser with a wavelength of 650 nm over masseter muscle region. Group 2 (Nd: YAG laser, n = 15) were treated with Neodymium-doped Yttrium Aluminium Garnet laser with a wavelength of 1064 nm and the same protocol with Nd: YAG laser was performed in the Group 3 (placebo, n = 15) using sham device.
View Article and Find Full Text PDFACS Omega
January 2025
Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
Carbon dots (CDs) derived from natural products have attracted considerable interest as eco-friendly materials with a wide range of applications, such as bioimaging, sensors, catalysis, and solar energy harvesting. Among these applications, electroluminescence (EL) is particularly desirable for light-emitting devices in display and lighting technologies. Typically, EL devices incorporating CDs feature a layered structure, where CDs function as the central emissive layer, flanked by charge transport layers and electrodes.
View Article and Find Full Text PDFChem Soc Rev
January 2025
Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstrasse 66, 01062 Dresden, Germany.
Nanoporous solids offer a wide range of functionalities for industrial, environmental, and energy applications. However, only a limited number of porous materials are responsive, the nanopore dynamically alters its size and shape in response to external stimuli such as temperature, pressure, light or the presence of specific molecular stimuli adsorbed inside the voids deforming the framework. Adsorption-induced structural deformation of porous solids can result in unique counterintuitive phenomena.
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