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oe1(光电查) - 科学论文

380 条数据
?? 中文(中国)
  • Scintillation Properties of Ce3+ Doped Silicon-Magnesium-Aluminum-Lithium Glass Scintillators by using Radiation Sources

    摘要: Glass scintillators can be doped with different elements to improve their luminescence properties. In this study, we present 0.5 wt% Ce3+-doped (58?x)SiO2-4MgO-18Al2O3-20Li2O and (58?x)SiO2-4MgO-18Al2O3-20LiF glass scintillators. We used a pulsed laser to measure the laser-induced emission spectrum and the decay time with decreasing temperature from 300 K to 10 K. The light intensity of both glass samples increased with decreasing temperature from 300 K to 10 K. Additionally, the two glass samples exhibited a fast decay time of approximately 25 ns. In the photo-induced spectrum, an excitation peak at 312 nm and two emission peaks, at 370 nm and 700 nm, were observed in both the glass samples. The X-ray-induced emission intensity of former is approximately six times higher than that of latter, and only former glass sample exhibits a proton-induced emission spectrum.

    关键词: Luminescence,Decay time,Ce3+,Glass scintillator

    更新于2025-11-25 10:30:42

  • Investigation on the crack fracture mode and edge quality in laser dicing of glass-anisotropic silicon double-layer wafer

    摘要: This work puts forward numerical and experimental investigations on laser dicing of glass-anisotropic single-crystal silicon double-layer wafer using laser induced thermal-crack propagation (LITP). A semiconductor continuous wave laser working at the defocusing mode serves as volumetric heat source for glass layer while as surface heat source for silicon layer. Based on the classical fracture theory, a static seam-type crack is introduced under the circumstance of ABAQUS to simulate the crack fracture modes in glass layer as well as silicon layer with crystal planes of (100), (110) and (111) during laser dicing in different dicing directions. In the experiments, processing parameters are kept the same as the simulations and typical dicing directions obtained from simulations are also used. The surface morphologies of crack edges are measured by the optical microscope and surface profiler. Through the comparison of numerical and experimental results it is discovered that for the specific substrate, the evolution of crack edge qualities in different dicing directions and different layers can be interpreted based on the corresponding stress distribution and stress intensity factor (SIF) ratio explicitly. And most important of all, the anisotropy of silicon layer has significant influence on the fracture mode and edge quality of crack in both layers.

    关键词: Crack fracture mode,Laser induced thermal-crack propagation,Glass-anisotropic single-crystal silicon double-layer wafer,Crack edge quality,Static seam-type crack

    更新于2025-11-21 11:24:58

  • Velocity-dependent wear behavior of phosphate laser glass

    摘要: Using a reciprocating sliding tribometer, the velocity-dependent wear behaviors of phosphate laser (PL) glass were investigated in dry and humid air. The experimental results show that the velocity dependence of wear in PL glass is very sensitive to the presence of water. In dry air, the velocity-dependent wear of PL glass shows fracture-dominated damage behavior. With increasing velocity, the Hertzian cracks increase ?rst and then tend to saturation. Simultaneously, the material-removal volume also increases ?rst and then keeps almost unchanged. However in humid air, the wear mechanism transforms into tribochemistry-controlled wear process, and almost no crack forms on glass surface for various velocities. With increasing velocity, the stress-enhanced hydrolysis becomes weaker and material-removal volume of PL glass decreases sharply. These results may help understand the surface damage and material removal of phosphate laser glass during machining and serving in various conditions.

    关键词: Water,Phosphate glass,Velocity,Crack,Tribochemical wear

    更新于2025-11-21 11:18:25

  • A facile dopamine-assisted method for the preparation of antibacterial surfaces based on Ag/TiO2 nanoparticles

    摘要: Highly effective antibacterial surfaces are crucial to prevent bacterial infections. In this work, we developed a simple method based on Ag/TiO2 nanoparticles via a dopamine-assisted process with long-term antibacterial efficacy, for the preparation of antibacterial glass surfaces. The chemical and morphological features of the prepared surfaces were investigated through field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, X-ray diffraction, and X-ray photoelectron spectrometry. The ultraviolet-visible spectroscopy absorption spectra of the prepared glass samples were measured with a spectrophotometer. The prepared Ag/TiO2 nanoparticle modified surfaces exhibited high activity in the elimination of the Gram-negative Escherichia coli and Gram-positive Bacillus subtilis bacteria under visible light and still maintained good antibacterial properties against E. coli after immersion in phosphate buffered saline solution for 60 days.

    关键词: Silver,Dopamine,Titanium dioxide,Glass,Antibacterial property

    更新于2025-11-21 11:08:12

  • One-Pot Synthesis of Gel Glass Embedded with Luminescent Silicon Nanoparticles

    摘要: Preparation of highly luminescent glasses involves expensive and complicated processes and usually requires high temperature. In this work, we show that luminescent silicon (Si) nanoparticle (NP)- embedded silicate gel glasses can be developed under near-ambient conditions by a remarkably simple, one-pot strategy, without using any sophisticated instrumentation or technique. Simultaneous hydrolysis and reduction of (3-aminopropyl)triethoxysilane leads to the formation of colloidal Si nanocrystals that can be transformed to a glassy phase upon slow evaporation followed by freezing. Structural investigations reveal the formation of a sodium silicate gel glass framework having discernible shear bands, along with embedded Si NPs. High photoluminescence quantum yield (ca. 35?40%), low glass-transition temperature (Tg ≈ 66?73 °C), strain-tolerant mechanical stability, and inexpensive preparation make the glass attractive for applications as display materials and photonic converters.

    关键词: luminescence,silicon,gel glass,nanoparticles,photon conversion

    更新于2025-11-21 11:01:37

  • Highly efficient rare-earth-free deep red emitting phosphor La <sub/>2</sub> Li <sub/>1?y</sub> Sb <sub/>1?x</sub> O <sub/>6</sub> : <i>x</i> Mn <sup>4+</sup> , <i>y</i> Mg <sup>2+</sup> : application in high-power warm w-LEDs

    摘要: Phosphor-in-glass (PiG), which serves as both a luminescent convertor and organic encapsulation material in high-power white light-emitting diodes (w-LEDs), has become a prospective research hotspot owing to its high transparency and thermal stability. However, YAG:Ce3+ PiG-based LED devices still suffer from a lack of a red component. Therefore, the development of red phosphors with excellent quantum efficiency and superior thermal stability is urgent. Herein, a highly efficient La2Li1?ySb1?xO6:xMn4+,yMg2+ red phosphor with a broadband emission ranging from 670 to 720 nm was fabricated via a conventional solid-state reaction. By co-doping Mg2+ in La2LiSbO6:Mn4+, the emission intensity was enhanced significantly, which reaches as high as 10 times that of the single-doped La2LiSbO6:Mn4+. It is proposed that the Mg2+ dopant can compensate imbalanced charges for the substitution of Sb5+ by Mn4+ and interrupt adverse energy transfer among the Mn4+ activators. Impressively, a maximum quantum yield of up to 80.3% is achieved and about 80% emission intensity is retained at the temperature of 423 K. Furthermore, the crystal field strength (Dq) and Racah parameters (B and C) together with the nephelauxetic ratio (b1) were calculated based on the obtained spectroscopic data. By embedding the red-emitting La2LiSbO6:Mn4+,Mg2+ phosphor and yellow-emitting YAG:Ce3+ phosphor into TeO2-based glass, an inorganic PiG composite as a color converter to replace organic silicone was acquired. The excellent optical parameters and tunable chromaticity feature of the fabricated w-LEDs were achieved by adjusting the mass ratio of La2LiSbO6:Mn4+,Mg2+ to YAG:Ce3+ in the PiG plate, where the correlated color temperature changed from cool white (6555 K) to warm (4130 K) and the color rendering index increased from 73.7 to 86.6 under an operating current of 300 mA.

    关键词: Phosphor-in-glass,quantum yield,red phosphor,Mg2+,thermal stability,w-LEDs,Mn4+

    更新于2025-11-20 15:33:11

  • Robust CsPbX <sub/>3</sub> (X = Cl, Br, and I) perovskite quantum dot embedded glasses: nanocrystallization, improved stability and visible full-spectral tunable emissions

    摘要: Currently, all inorganic perovskite quantum dots (QDs) of cesium lead halides (CsPbX3, X = Cl, Br, and I) have been mainly fabricated using wet chemical methods. Unfortunately, applications of perovskite QDs have been limited due to their poor stability. In the present work, the in situ growth of whole-family CsPbX3 (X = Cl, Br, and I) perovskite QDs in Zn–P–B–Sb based oxide glass via a glass crystallization strategy is reported. The as-prepared CsPbX3 QDs@glass nanocomposites exhibit typical excitonic recombination emissions and superior chemical stability benefited from the protection of the robust inorganic glass matrix. Through modifying the molar ratio of halide sources in glass, multi-color tunable emissions in the entire visible spectral range of 400–750 nm are achieved. As a result, light-emitting diode devices can be constructed by coupling blue-emissive CsPbBrCl2, green-emissive CsPbBr3 and red-emissive CsPbBr0.5I2.5 QDs@glass powders with a commercial ultraviolet chip, yielding bright white light luminescence with excellent optoelectronic performance.

    关键词: stability,light-emitting diodes,tunable emissions,glass crystallization,perovskite quantum dots

    更新于2025-11-20 15:33:11

  • Near-Infrared-Laser-Driven Robust Glass-Ceramic-Based Upconverted Solid-State-Lighting

    摘要: Laser lighting, generally consisting of blue laser and downconversion phosphors, is considered to be the next promising illumination to replace traditional LED lighting. However, the irradiation of high-power blue laser will inevitably cause significant thermal attack, which puts forward high demand on phosphor converters as well as device architecture. In this work, a proof-of-concept prototype of near-infrared laser-driven upconversion solid-state-lighting is proposed. Robust lanthanide doped α/β-NaYF4 embedded glass ceramics are developed as upconverted color converters and routine 980 nm laser is used as pumping source for its relatively low thermal effect and a perfect resonance with Yb3+ sensitizers. Stable and bright upconversion white light is indeed produced by coupling Yb/Tm/Er doped α-NaYF4 glass ceramic with 980 nm laser but the luminous efficiency and energy efficiency are only 0.3 lm/W and 0.12%, respectively, owing to low Er doping concentration. As an alternative, a stacking structure of Yb/Tm doped glass ceramics and Yb/Er doped one is designed as color converter to improve luminous efficiency up to 1.0 lm/W and energy efficiency of 0.5% under a laser power density of 275 W/cm2. It is believed that this research will provide a new idea for laser lighting and open the application field of glass ceramics.

    关键词: upconversion,lanthanide ions,optical materials,glass ceramics,laser lighting

    更新于2025-11-20 15:33:11

  • Energy transfer behaviors and tunable luminescence in Tb3+/Eu3+ codoped oxyfluoride glass ceramics containing cubic/hexagonal NaYF4 nanocrystals

    摘要: For glass ceramics, glass crystallization and doping activators into nanocrystalline phases are the key factors determining optical performance, including energy transfer (ET) process. Herein, we propose a strategy to verify ET behaviors based on glass crystallization, elaborately selecting phase-transformed NaYF4: Tb3+, Eu3+ nanocrystals embedded transparent glass ceramics as a typical example. The ET behaviors from Tb3+ to Eu3+ are clarified via photoluminescence spectra, time-resolved spectra and decay curves. Impressively, the corresponding ET process in cubic NaYF4 turns out to be more efficient than that in hexagonal, in spite of a disorder-to-order transformation from cubic to hexagonal. The reason for this abnormal ET efficiency is that dopants prefer to be partitioned into the cubic NaYF4 rather than the hexagonal one during glass crystallization. This work provides keen insights into the relationship between glass crystallization and ET behaviors, which can also feed back to helpfully guide the design and fabrication of glass ceramics with superior optical performance.

    关键词: glass crystallization,cubic/hexagonal NaYF4,energy transfer

    更新于2025-11-20 15:33:11

  • Up-conversion luminescence and highly sensing characteristics of Er3+/Yb3+ co-doped borophosphate glass-ceramics

    摘要: Er3+/Yb3+ co-doped phosphate glass ceramics (GC) with a cubic KAlSi2O6 type structure were successfully fabricated by traditional melt-quenching technique and subsequent heat treatment. Structural characterization of the GC was achieved by X-ray powder diffractometer (XRD) combined with transmission electron microscope (TEM). The up-conversion (UC) optical properties were systemically investigated through absorption spectra, photoluminescence spectra, pump power dependent UC emission spectra, and UC decay curves. The possible energy transfer process and the transition channels were analyzed by using energy level diagram. Results show that the UC luminescence performance of the GC was enhanced compared to precursor glass (PG). Moreover, the temperature dependent UC emission spectra of the GC were measured in the temperature range of 298–798K under 980 nm laser excitation. Combined with the fluorescence intensity ratio (FIR) technique, the UC emissions of Er3+/Yb3+ co-doped GC with two thermally coupled energy levels (TCELs) of 525 nm (Er3+:2H11∕2→4I15∕2) and 549 nm (Er3+:4S3∕2→4I15∕2) were studied as a function of temperature in the range of 298–798K. For optimized Er3+/Yb3+ co-doped GC, the theoretical maximum value of relative sensitivity Sr?max is 1.67 % K?1 at 298 K, and absolute sensitivity Sa?max is 4.59 ×10?3 K?1 at 570 K, which indicates that the Er3+/Yb3+ co-doped phosphate GC is a very promising candidate for optical temperature sensors with higher sensitivity.

    关键词: Glass ceramic,Optical thermometric,Up-conversion

    更新于2025-11-20 15:33:11