JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Tiansong Dai,Guifang Ju,Yang Lv,Yahong Jin,Haoyi Wu,Yihua Hu
Here, a new LiYGeO 4 : Eu 3+ phosphor exhibiting long red persistent luminescence (PerL) is developed herein. Experimental results show that LiYGeO 4 : Eu 3+ with a low doping concentration of Eu 3+ emits high-intensity red PerL, which lasts for more than 21 h. The red PerL of the preirradiated LiYGeO 4 : Eu 3+ phosphor can be repeatedly excited to increase its intensity via short-term stimulation using low-energy near-infrared (NIR) light. Furthermore, LiYGeO 4 : Eu 3+ exhibits strong intrinsic emission, enhancing the f-f emission of Eu 3+ . The PerL emission, photoluminescence (PL) emission, and thermoluminescence (TL) spectra are identical, suggesting the emission originating from the host and Eu 3+ center. TL measurements were conducted to intensively study the trap characteristics of LiYGeO 4 : Eu 3+ using the Booth-Bohun and T m -T stop methods. Results reveal the underlying mechanism of the PerL and the importance of Eu 3+ as the introduced traps in LiYGeO 4 : Eu 3+ . LiYGeO 4 : Eu 3+ with a high doping concentration of Eu 3+ exhibits excellent PL properties and thermal stability, with its quantum efficiency surpassing those of commercial phosphors such as Y 2 O 3 : Eu 3+ , suggesting its potential application in solid-state lighting. Thus, the doping of LiYGeO 4 : Eu 3+ with low and high concentrations of Eu 3+ can be helpful in fabricating materials exhibiting different luminescence properties.
研究领域:
材料科学
·
光学
·
光子学
✓ 已验证
DOI
高影响因子
Science Advances
·
2019
·Vol. 5
·期 1
·
IF 12.804
Ming Zhao,Zhiguo Xia,Xiaoxiao Huang,Lixin Ning,Romain Gautier,Maxim S. Molokeev,Yayun Zhou,Yu-Chun Chuang,Qinyuan Zhang,Quanlin Liu,Kenneth R. Poeppelmeier
Solid-state phosphor-converted white light-emitting diodes (pc-WLEDs) are currently revolutionizing the lighting industry. To advance the technology, phosphors with high efficiency, tunable photoluminescence, and high thermal stability are required. Here, we demonstrate that a simple lithium incorporation in NaAlSiO4:Eu system enables the simultaneous fulfillment of the three criteria. The Li substitution at Al sites beside Na sites in NaAlSiO4:Eu leads to an enhanced emission intensity/efficiency owing to an effective Eu3+ to Eu2+ reduction, an emission color tuning from yellow to green by tuning the occupation of different Eu sites, and an improvement of luminescence thermal stability as a result of the interplay with Li-related defects. A pc-WLED using the Li-codoped NaAlSiO4:Eu as a green component exhibits improved performance. The phosphors with multiple activator sites can facilitate the positive synergistic effect on luminescence properties.
研究领域:
材料科学
·
光电子学
·
固态照明
·
无机化学
·
发光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 10
·2495-2501
·
IF 5.976
Youling He,Jiangling He,Zhonghang Yu,Haoran Zhang,Yingliang Liu,Guangqi Hu,Mingtao Zheng,Hanwu Dong,Jianle Zhuang,Bingfu Lei
Carbon dot (CD)-based solid-state fluorescent materials have attracted a lot of attention in recent years owing to their superior optical and environmentally friendly properties, demonstrating a potential use in many applications. However, previously reported CD-based solid-state fluorescent materials mostly assemble a type of CD in the matrix which has only a single characteristic peak, and those of assembled double CDs with two characteristic peaks are very rare. Such a drawback restricts their further application, particularly in the field of white light emitting diodes (WLEDs). Herein, a rare type of double CD-based fluorescent material has been synthesized with dual characteristic peaks at 420 nm and 635 nm via the one-step assembly of blue- and red-emissive carbon dots (bCDs, rCDs) into mesoporous aluminas (MAs). The MA non-fluorescent matrix neither competes for absorbing excitation light nor absorbs the emission from the CDs, leading to excellent PL emitting properties and color and thermal stabilities. The emissive colors are tunable in the white-light region simply through adjusting excitation wavelengths, showing their great potential for phosphor-based WLEDs. In the field of agricultural planting, transparent sunlight conversion films based on co-assembled phosphors have been obtained, revealing inherent optical properties and an efficient process for converting sunlight into blue and red lights, which are essential for plant photosynthesis.
研究领域:
材料科学
·
光电技术
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
Science of Advanced Materials
·
2017
·
IF 1.671
Zhou Zhiping,Yu Yingsen,Sun Quanmin,Liu Xiaotang,Lei Bingfu,Yan Yun
In this work, up-conversion phosphor CaF2:Yb3
+, Er3+ was synthesized by the co-precipitation method. X-ray Diffraction (XRD) and Photoluminescence Spectra (PL) were used to characterize the samples. The effects of annealing temperature and
Yb3+ and Er3+ concentrations on the luminescence properties were discussed. Strong green and red light were obtained under 980 nm laser excitation, the optimal annealing temperature was 600 °C, while the optimal doping concentration was 8 mol% Yb3+ and
0.6 mol% Er3+. The green (540 nm and 552 nm) and red (652 nm and 669 nm) up-conversion luminescence peaks can be ascribed to the transitions of 4S3/2-4I15/2 and 4F9/2-4I15/2, respectively. The
up-conversion luminescence intensities of the green and red emitting peaks can be changed by adjusting the concentration ratio of Yb3+ and Er3+. Hence, it can potentially be used as the red light conversion agent. The dependence of up-conversion intensities (CaF2:Yb3+,
Er3+) on excitation power indicated that two-photon absorption processes were responsible for green and red luminescence.
研究领域:
材料科学
·
光学
·
光子学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 44
·2303765
·
IF 19
Xiang Li,Hong Wang,Jian Chen,Yong Tian,Chongchen Xiang,Wanqiang Liu,Zhihua Zhou,Jiaxi Cui,Xudong Chen
Photoswitchable fluorescent polymers (PFPs) are emerging as a class of promising systems for photowritable pattern, optical anti-counterfeiting, and information encryption. They typically use harmful UV light as the stimulus, which often leads to inevitable photobleaching and poor reversibility. To address this issue, visible-light-driven PFPs by copolymerization of novel negative photochromic spiropyran monomer and methyl acrylate are developed. The obtained copolymers display bright red fluorescence, which can be reversibly turned off by visible light irradiation. Many appealing features are observed in this system, including fast photo-responsibility, prominent photo-reversibility and photostability, simple preparation process, and processability. Their applications in photorewritable patterns, optical anti-counterfeiting, and information encryption are also demonstrated.
研究领域:
材料科学
·
光电
·
化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 50
·期 1
·1452-1460
·
IF 5.2
Shangwei Wang,Ran Pang,Xuexia Chen,Tao Tan,Qi Wang,Chengyu Li,Su Zhang,Taixing Tan,Hongpeng You,Hongjie Zhang
Near-infrared phosphor conversion light-emitting diode (NIR pc-LED) is a widely used ideal NIR light source due to its unique advantages of low cost, energy saving, compactness and long operational lifetime. However, there is currently a scarcity of appropriate phosphor for NIR light sources utilized in spectral detection, with emission peak larger than 850 nm and steady spectrum output of ultra broadband spectra. Here, a broadband Cr 3+ activated LiScSnO 4 (LSS) phosphor ( λ ex-max = 460 nm) matching the pump band of commercial blue LED chips has been developed, which shows a long wavelength NIR emission peaking at 900 nm. Cr 3+ simultaneously replace the Wyckoff site co-occupied by Sc and Sn in LSS. Due to the difference of local environment of the specific crystal field , two different wide emission bands are caused. These two broad emission bands both contribute to the broadband luminescence with a full width at half maximum (FWHM) of 227 nm. Benefiting from the crystallography consistent Wyckoff position occupation of Cr 3+ ions, the spectral distribution of LSS:Cr 3+ exhibit excellent stability over a wide temperature span (80–423 K). The broadband NIR pc-LED prototype based on LSS:Cr 3+ shows great potential in NIR spectrum detection, night vision imaging applications.
研究领域:
材料科学
·
光学工程
·
固态物理
·
光电子学
·
分析化学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 29
·15791-15799
·
IF 6.895
Hao-Hua Deng,Qiong-Qiong Zhuang,Kai-Yuan Huang,Paramasivam Balasubramanian,Zhen Lin,Hua-Ping Peng,Xing-Hua Xia,Wei Chen
As a new emerging candidate for solid-state phosphors, copper nanoclusters (CuNCs) have gained tremendous interest in the field of white light-emitting devices (WLEDs). However, their further applications are impeded by the low photoluminescence quantum yield (PLQY) and poor emission color tunability of CuNCs. This work demonstrates the synthesis of cyan and orange emitting CuNCs, and their combination as color conversion phosphors in WLEDs. The cyan and orange emitting CuNCs were prepared employing 2-mercapto-1-methylimidazole (MMI) and N-acetyl-L-cysteine (NAC), respectively, as stabilizing-cum-reducing agents. The dispersions of MMI-CuNCs and NAC-CuNCs are weakly emissive. However, after processing into powders, they both possess ultrahigh PLQYs (45.2% for MMI-CuNCs, and 64.6% for NAC-CuNCs) owing to the effect of aggregation-induced emission (AIE). All-CuNC based WLEDs are then designed and developed using powdered MMI-CuNC and NAC-CuNC samples on commercially available 365 nm GaN LED chips. They display acceptable white light characteristics with a Commission Internationale de l'Eclairage coordinate value and color rendering index of (0.26, 0.30) and 83, respectively. We believe that these cost-effective and eco-friendly CuNCs with interesting AIE properties will vigorously promote the development of high-quality WLEDs for commercial applications.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 26
·期 3
·2472-2477
·
IF 3.3
Yingui Gao,Zhihuang Xu,Liwang Ye,Yuanjie Wang,Xinxin Zhuang
Lead-free metal halides are considered as alternatives to lead-based perovskites due to their low toxicity, rich structural diversity, and high luminescence properties. We report millimeter-sized single crystals of a new zero-dimensional (0D) copper(I)-based hybrid material, (AEP)2Cu2Br6·2Br·2H2O (AEP = C6H18N33+), which exhibits bright broadband green photoluminescence (PL) at 510 nm with a Stokes shift of 220 nm and a PL lifetime of 121.1 μs. Density functional theory (DFT) calculations and experimental studies reveal that the green light can be attributed to self-trapping exciton (STE) emission. It is worth mentioning that this crystal has a high photoluminescence quantum yield (PLQY) of 90.5%, which is higher than most copper halides.
研究领域:
材料科学
·
光电学
·
光子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS & DESIGN
·
2019
·
IF 5.77
Ran Cai,Meng Nie,Feng Xu
To facilitate progression from the laboratory to commercial applications, it will be necessary to develop facile and scalable methods to produce high-quality quantum dots (QDs) of layered two-dimensional materials (LTMs). In this paper, we for the first time report a turbulence-induced disintegration method to prepare ultra-small BN and WS 2 QDs, which can easily be achieved only using a household kitchen blender to directly disintegrate their bulk counterparts in liquids. The resulting ultra-small BN and WS 2 QDs exhibit excellent photoluminescence and photo-thermal converting properties, respectively. As proof-of-concept applications, these properties have great promise in cell-imaging probes and photo-thermal therapy. This work not only provides successful paradigms for preparing the QDs of other LTMs but also demonstrates potential applications for the QDs.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2015
·Vol. 5
·期 4
·1494-1502
·
IF 1.484
Wangqing Shen,Yiwen Zhu,Zhengling Wang
Sr4Si3O8Cl4co-doped with Eu2+, Bi3+were prepared by the high temperature reaction. The structure and luminescent properties of Sr4Si3O8Cl4:Eu2+, Bi3+were investigated. With the introduction of Bi3+, luminescent properties of these phosphors have been optimized. Compared with Sr3.90Si3O8Cl4:0.10Eu2+, the blue-green phosphor Sr3.50Si3O8Cl4:0.10Eu2+, 0.40Bi3+shows stronger blue-green emission with broader excitation in near-UV range. Bright blue-green light from the LED means this phosphor can be observed by the naked eye. Hence, it may have an application in near UV LED chips.Keywords:luminescent properties;phosphors;light-emitting diodes;Sr4Si3O8Cl4
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2016
·
IF 13.038
Hujia Cao,Junliang Ma,Lin Huang,Haiyan Qin,Renyang Meng,Yang Li,Xiaogang Peng
Single-molecular spectroscopy reveals that photoluminescence (PL) of a single quantum dot blinks, randomly switching between bright and dim/dark states under constant photoexcitation, and quantum dots photobleach readily. These facts cast great doubts on potential applications of these promising emitters. After ∼20 years of efforts, synthesis of nonblinking quantum dots is still challenging, with nonblinking quantum dots only available in red-emitting window. Here we report synthesis of nonblinking quantum dots covering most part of the visible window using a new synthetic strategy, i.e., confining the excited-state wave functions of the core/shell quantum dots within the core quantum dot and its inner shells (≤ ∼5 monolayers). For the red-emitting ones, the new synthetic strategy yields nonblinking quantum dots with small sizes (∼8 nm in diameter) and improved nonblinking properties. These new nonblinking quantum dots are found to be antibleaching. Results further imply that the PL blinking and photobleaching of quantum dots are likely related to each other.
研究领域:
材料科学
·
纳米技术
·
光学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 22
·期 2
·311-319
·
IF 3.382
Wei Wang,Hang Yang,Yixin Liu,Xiaohan Yun,Yi Wei,Guogang Li
Establishing effective methods to optimize luminescent materials has been a significant challenge for white light-emitting-diode (WLED) applications. Herein, we successfully realized the adjustment of the photoluminescence and enhancement of the thermal stability of Ln3+ (Ln3+ = Ce3+, Eu3+)-doped Ca10−x/yBax/y(PO4)6O phosphors. First, Ba2+ ions from raw BaCO3 material realized a spectral red shift from 464 nm to 506 nm, which we suggested to be due to a synergistic effect from a centroid shift and crystal field splitting. When using BaHPO4 as a raw material, the PL intensity was 6.5 times that of the initial intensity. Surprisingly, the thermal stability was also improved, which was attributed to the increasing lattice distortion introducing many traps. Second, the Ca10(PO4)6O:Eu3+ red phosphor exhibited an abnormal emission phenomenon involving the 5D0 → 7F0 peak at 575 nm becoming the strongest emission peak and the 5D0 → 7F1 peak at 585 nm becoming particularly weak. The site symmetry and charge transfer states were speculated to be closely related to this phenomenon. The charge transfer states were not only correlated with the crystal field strength, but also related to f-electron delocalization, which significantly influenced the energy-level structure of Eu3+. More importantly, according to the relationship between the I(5D0 → 7F0)/I(5D0 → 7F1) ratio and the lattice structure, Eu3+ in the Ca10(PO4)6O compound could be applied as a probe to explore the matrix information, which would provide a helpful method to investigate the lattice structures of compounds and also guide researchers to design new suitable red phosphors.
研究领域:
材料科学
·
光学材料
·
无机化学
·
固体物理
·
发光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）