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Near-infrared laser driven white light continuum generation: materials, photophysical behaviours and applications
摘要： The pursuit of efficient light sources has stimulated continued effort in the search of materials and methods for generating white light emission. In addition to the white light produced by light-emitting diodes (LEDs) and fluorescent lamps that involves spectral conversion of high energy to low energy emission, recent studies showed that it was also possible to produce white visible light by irradiating different active materials with near-infrared (NIR) constant-wave (CW) lasers. In this review, we begin by introducing and categorizing different materials that exhibit NIR laser driven white light emission, including normal inorganic phosphors, organometallic compounds, graphene, etc. We then discuss the photophysical behavior of this process in terms of optical spectra, temperature evolution and photoelectric response. Different mechanisms of while light generation are analyzed afterwards, and the possibility of a more general physical picture of this process is discussed. This review is concluded with a summary of the current understanding and discussion on potential applications and future perspectives.
关键词： graphene,near-infrared laser,optical spectra,photoelectric response,organometallic compounds,temperature evolution,inorganic phosphors,photophysical behavior,white light emission
更新于2025-09-23 15:19:57
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Tailoring of structural and photoluminescence emissions by Mn and Cu co-doping in 2D nanostructures of ZnS for the visualization of latent fingerprints and generation of white light
摘要： Tailoring of structural and photoluminescence emissions by Mn and Cu co-doping in 2D nanostructures of ZnS for the visualization of latent fingerprints and generation of white light. There has been a recent demand for the development of luminescent materials for visualizations of latent fingerprints (LFPs) for achieving enhanced security. Also recently, there has been a new research trend in the development of 2D materials from non-layered semiconductors with strong luminescence properties in the visible region. The conventional growth process of luminescent materials limits their capacity of tuning the structure and light emission efficiency. However, multi-atom doping provides an additional degree of freedom to tune the basic morphologies and optical properties of luminescent semiconductors by controlling the defect levels. Here, by using a simple chemical technique, multi-atom (Cu and Mn) doped rarely reported 2D nanosheets of zinc sulphide (ZnS) have been grown. Thus, a stable high fluorescence efficiency of ～62% in the visible region has been realized for the visualization of LFPs. Furthermore, near-white light emission has been demonstrated by coating the synthesized materials with a suitable doping concentration on a commercially available UV-LED chip. The proposed technique may be utilized further to build up other 2D nanostructured materials for multifunctional applications in solid state lighting, LFPs and forensic science.
关键词： ZnS,2D materials,latent fingerprints,co-doping,luminescent materials,white light emission
更新于2025-09-19 17:15:36
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Rare earth-free composites of carbon dots/metal-organic framework as white light-emitting phosphor
摘要： Over the last few years, numerous efforts have been made to develop white light-emitting metal-organic frameworks (MOFs), due to the useful features of MOFs such as ultrahigh surface areas and tunable pore architecture. However, rare earth (RE) ions are most commonly applied as phosphors in these materials so far, raising device cost and environmental concerns. Here, we designed a new type of RE-free material capable of white light-emission upon excitation at 365 nm, with the photoluminescence quantum yield in solid state reaching 37%, fabricated by compositing carbon dots (CDs) with Zr(IV)-based MOF. WLEDs constructed by depositing the CDs/Zr-MOF nanocomposite on a commercial UV LED chip feature a CIE chromaticity coordinate at (0.31, 0.34), high color rendering index (CRI) of 82, and luminous efficiency of 1.7 lm/W.
关键词： carbon dots,rare-earth-free luminophores,white-light-emission,Zr-MOFs,down-conversion LEDs
更新于2025-09-19 17:15:36
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Measuring the impact of surgical intervention on pediatric pectus excavatum using white light scanning
摘要： Background: Objective preoperative assessment of pectus excavatum (PE) deformity in patients is limited to preoperative measurement of severity using computed tomography (CT) or magnetic resonance imaging (MRI). Postoperative assessment is currently subjective as postoperative CT scans are not recommended in light of radiation exposure and high cost to families. White Light Scanning (WLS) is a novel 3D imaging modality that offers an alternative that is a quick, nonionizing, inexpensive, and safe strategy for measurement both pre- and postsurgery. Our prior investigation demonstrated the feasibility of using WLS to measure PE deformity and showed very strong correlation of a new WLS-derived PE severity index, the Hebal–Malas Index (HMI), with CT-derived HI. The purpose of this study was to demonstrate use of WLS to assess extent of correction of PE deformities after the Nuss procedure. Methods: WLS scan data were gathered prospectively in pediatric patients with PE from 2015 to 2018. HMI was obtained from the preoperative and postoperative WLS scans. Analysis assessed the differences of preoperative and postoperative HMI. Preoperative CT-derived HI was collected from the medical record and estimated postoperative Haller Index was calculated from HMI and correlation of HMI and HI using historical data. Results: A total of 71 patients received a preoperative CT scan and underwent surgery for PE. Of those, 63 (89%) received WLS preoperatively and 51 (72%) had complete preoperative and postoperative WLS data. The average postoperative decrease in the WLS-derived HMI was 0.35 (SD: 0.15) and 1.73 (SD: 1.03) in WLS-estimated HI. Conclusions: WLS is highly effective in objectively quantifying the extent of surgical correction in PE patients. Level of evidence: IV Type of study: Diagnostic Study
关键词： White light scanning,Nuss procedure,Correction index,Pectus excavatum,Pectus excavatum repair
更新于2025-09-19 17:15:36
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Facile, Gram-Scale and Eco-friendly Synthesis of Multi-Color Graphene Quantum Dots by Thermal-Driven Advanced Oxidation Process
摘要： Graphene quantum dots (GQDs) have been demonstrated of great potential and benefits in the fields of bioimaging and white light-emitting-diodes (WLEDs). However, it is still highly demanding at the current level to solve the dilemma of achieving high-yield GQDs of good quality and superior fluorescent property using low-cost sustainable and industrializable production procedure. In this work, we for the first time report the gram-scale synthesis of well-crystalline GQDs with ultra-small size based on thermal-driven Advanced Oxidation Process (AOP) under facile green hydrothermal conditions. The average yield calculated from 20 trials reached up to 60%, and the average size of the dots was measured to be ~3.7 nm. Furtherly, GQDs with the photoluminescence (PL) emission of blue, green, yellow, orange, and red have been prepared by expanding the π-conjugation and introducing graphite nitrogen in the carbon skeleton based on chemical structure engineering. The PL-tunable GQDs have an average size distribution of 2~5 nm and a lamellar structure of 2~6 layers. Structure analysis results have indicated that the red shift of PL emission is attributed to bandgap narrowing. This approach successfully converts the easily available and cheap precursor into high-valued products with great application potentials. The PL-tunable GQDs have been successfully used as fluorescent probes of good biocompatibility for in vitro/ in vivo bio-imaging and to produce highly-photostable white-light-emitting composite film with a quantum yield (QY) of 24%.
关键词： Gram-scale synthesis,White light-emitting-diodes,Photoluminescence,Bioimaging,Advanced Oxidation Process,Graphene quantum dots
更新于2025-09-19 17:13:59
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Highly Efficient Cyan-Green Emission in Self-Activated Rb <sub/>3</sub> RV <sub/>2</sub> O <sub/>8</sub> (R = Y, Lu) Vanadate Phosphors for Full-Spectrum White Light-Emitting Diodes (LEDs)
摘要： Phosphor-converted white-light-emitting diodes (pc-WLEDs) rely on combining a near-ultraviolet (n-UV) or blue chip with trichromatic and yellow-emitting phosphors. It is challenging to discover cyan-green-emitting (480?520 nm) phosphors for compensating the spectral gap and producing full-spectrum white light. In this work, we successfully discovered two unprecedented bright cyan-green emitting Rb3RV2O8 (R = Y, Lu) phosphors that gives emission bands centered at 500 nm upon 362 nm n-UV light excitation. Interestingly, the both self-activated compounds exhibit high internal quantum e?ciencies (IQEs) of 71% for Rb3YV2O8 and 85% for Rb3LuV2O8, respectively. Moreover, controllable emission color can be successfully tuned from cyan-green to orange-red across the warm white light region by design strategy of VO4 3? → Eu3+ energy transfer. The thermal quenching of as-prepared phosphors could be e?ectively mitigated by this design strategy. Finally, the as-fabricated n-UV (λ ex = 370 nm) pumped phosphor-converted (pc) W-LED devices utilizing Rb3RV2O8 (R = Y, Lu) along with commercial phosphors demonstrate well-distributed warm white light with high color-rendering index (CRI) of 91.9 and 93.5, and a low correlated color temperature (CCT) of 5095 and 4946 K. It suggests that the both vanadate phosphors have potential applications in full-spectrum pc-WLEDs.
关键词： cyan-green emission,self-activated,full-spectrum white light-emitting diodes,energy transfer,vanadate phosphors
更新于2025-09-19 17:13:59
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Tunable emission of cadmium-free transition metal (Cu, Mn, Ag) co-doped ZnInS/ZnS core-shell quantum dots
摘要： Color tunable quantum dots (QDs) based on the Cu, Mn, Ag co-doped ZnInS core and ZnS outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtained by using a one-pot synthesis followed by a hot injection with n-dodecanethiol (DDT) and oleylamine (OLA) as stabilizers in oil phase. Cu, Mn and Ag ions were introduced as single-dopant or co-dopants during the synthesis, providing an effective means to control the emission color of the QDs. The as-synthesized QDs showed photoluminescence emission ranging from green (530 nm) to near-red (613 nm), adjusted by doping components, dopant concentration, and Zn/In ratio. Importantly, quasi-white emission has been achieved by controlling the concentration of co-doped metal ions (Mn, Cu and Ag). The primary results demonstrated the promising potential of co-doped QDs as alternative materials for future high quality white LED applications.
关键词： doping,tunable emission,white light,core-shell,zinc group quantum dots
更新于2025-09-19 17:13:59
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Highly Elastic and >200% Reversibly Stretchable Downa??Conversion White Lighta??Emitting Diodes Based on Quantum Dot Gel Emitters
摘要： Combining the characteristics of different materials offers exciting new opportunities for advanced applications in various fields. Herein, white light-emitting diodes (WLEDs) with >200% reversible stretchability are fabricated using six-color quantum dots (QDs) gel emitters. Stable aqueous-phase alloy core/shell QDs with high quantum yield are obtained via ligand exchange using a ternary solvent system. Transparent and highly stretchable gels with large pores are created by binary-solvent-based gelation at low temperatures. Importantly, the QDs and the gel originate from the same two solvents, which make the QDs highly compatible with the gelation process. Consequently, QDs of six different colors are incorporated into the gel without any property degradation. The excellent optical properties of the QDs in the liquid phase (e.g., 17% higher photoluminescence (PL) intensity) are retained in the gel phase. The QD gel (QDG) exhibits elastic deformation up to 200%, with uniform PL over the entire gel. A down-conversion WLED built using the QDG emitter produces cool white light with a color temperature of 6100 K, a color rendering index of 94, and a luminous efficacy of 72 lm W?1. In addition, the performance of the QDG-based WLED remains unchanged even after more than 1000 bending/stretching cycles.
关键词： white light emitting diodes,gels,mechanical reliability,form factors,quantum dots
更新于2025-09-19 17:13:59
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Towards white light emission from a hybrid thin film of a self-assembled ternary samarium( <scp>iii</scp> ) complex
摘要： A new samarium complex [Sm(hfaa)3(Py-Im)] (ML) was synthesized by utilizing hexafluoroacetylacetone (hfaa) and 2-(2-pyridyl)benzimidazole (Py-Im) as coordinating ligands. A single crystal X-ray analysis shows that in the solid-state the complex dimerizes through intermolecular hydrogen-bonding with N–H···O (2.127 ?) and N–H···F (2.576 ?) interactions. The complex in the solid-state displayed highly monochromatic brilliant red emission with Commission International de I’Eclairage (CIE) color coordinates of 0.6532; 0.3336, with a remarkably long luminescence lifetime (≈ 204.47 ± 4.043 μs) and a high intrinsic quantum yield (≈ 6.60 %). Furthermore, the complex in different organic media displayed color tunability from orange (CIE; 0.6071; 0.3568) to violet (CIE; 0.3634; 0.2144) with from 105.50 ± 0.143 – 14.27 ± 0.033 μs. Hybrid and flexible thin films obtained by doping different concentrations (1%, 2%, 4% and 6%) of the complex into the poly(urethane) (PU) polymer matrix also exhibited color tunability from violet (CIE; 0.3380; 0.2162) to light orange (CIE; 0.5666; 0.3408). White light emission from a 1% doped thin film of the complex was realized by changing the excitation wavelength. The new material could be a potential candidate for the fabrication of full-color display devices and for solid-state lighting (SSL) applications.
关键词： luminescence,white light emission,color tunability,samarium complex,solid-state lighting
更新于2025-09-19 17:13:59
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Ca(Mg <sub/>0.8</sub> Al <sub/>0.2</sub> )(Si <sub/>1.8</sub> Al <sub/>0.2</sub> )O <sub/>6</sub> :Ce <sup>3+</sup> ,Tb <sup>3+</sup> Phosphors: Structure Control, Density-Functional Theory Calculation, and Luminescence Property for pc-wLED Application
摘要： A modified structure Ca(Mg0.8Al0.2)(Si1.8Al0.2)O6 (denoted as CMASO) from the evolution of CaMgSi2O6 (denoted as CMSO) codoped with Ce3+ and Tb3+ ions was designed successfully by solid reaction method for application in phosphor-converted white-light-emitting diode (pc-wLED). The Rietveld refinement of these two structures verified the changes derived from the replacement of some of the Mg2+ and Si4+ ions by Al3+ ions. The band gaps were calculated by density-functional theory (DFT) calculation method to verify the change of Al3+ ions replacing further, and the diffuse reflectance spectra (DRS) proved the veracity of the calculation result. The phosphors CMASO:Ce3+ showed blue emission excited by a wider excitation wavelength from 280 nm to 370 nm. The change of structure lead to the absorbable range broaden and the emission peak shifted to longer wavelength, compared with CMSO:Ce3+, although the amount of emitting center was the same. The reason for these phenomena was discussed in detail. The codoped phosphors CMASO:Ce3+,Tb3+ exhibited different emission colors from blue to green as the concentration of Tb3+ ions increased. Combined with commercial red phosphor CaAlSiN3:Eu2+ and ultraviolet LED (UV-LED) chips, the selected appropriate samples achieved white emission. The correlated color temperature (CCT) was 6137 K and the color rendering index (Ra) was 80.5, indicating that they could act as potential phosphors for possible applications in pc-wLED.
关键词： Ce3+,pc-wLED,DFT,luminescence property,Tb3+,Ca(Mg0.8Al0.2)(Si1.8Al0.2)O6,phosphor-converted white-light-emitting diode,density-functional theory
更新于2025-09-19 17:13:59