Nature Communications
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2023
·Vol. 14
·期 1
·1-12
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IF 16.6
Li Guowei,Jiang Shihui,Liu Aijun,Ye Lixiang,Ke Jianxi,Liu Caiping,Chen Lian,Liu Yongsheng,Hong Maochun
Crystal-field perturbation is theoretically the most direct and effective method of achieving highly efficient photoluminescence from trivalent lanthanide (Ln 3+ ) ions through breaking the parity-forbidden nature of their 4 f -transitions. However, exerting such crystal-field perturbation remains an arduous task even in well-developed Ln 3+ -doped luminescent nanocrystals (NCs). Herein, we report crystal-field perturbation through interstitial H + -doping in orthorhombic-phase NaMgF 3 :Ln 3+ NCs and achieve a three-orders-of-magnitude emission amplification without a distinct lattice distortion. Mechanistic studies reveal that the interstitial H + ions perturb the local charge density distribution, leading to anisotropic polarization of the F − ligand, which affects the highly symmetric Ln 3+ -substituted [MgF 6 ] 4− octahedral clusters. This effectively alleviates the parity-forbidden selective rule to enhance the 4 f –4 f radiative transition rate of the Ln 3+ emitter and is directly corroborated by the apparent shortening of the radiative recombination lifetime. The interstitially H + -doped NaMgF 3 :Yb/Er NCs are successfully used as bioimaging agents for real-time vascular imaging. These findings provide concrete evidence for crystal-field perturbation effects and promote the design of Ln 3+ -doped luminescent NCs with high brightness.
研究领域:
材料科学
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纳米技术
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光学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
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2019
·
IF 2.961
Yuan Zhong,Shujie Gai,Yimei Yang,Mao Xia,Ye Zhang,Fanshan Qiu,Fang Xiang,Zhi Zhou
Green phosphor is an essential component in phosphor-converted white light-emitting diodes (pc-LEDs). Herein, a novel green-emitting phosphate phosphor Sr 8 ZnY(PO 4 ) 7 :Eu 2+ (SZYP:Eu 2+ ) was synthesized through hydrothermal reaction method. The crystal structure, photoluminescence properties as well as thermal stability of SZYP:Eu 2+ were investigated systematically. SZYP:Eu 2+ can be efficiently excited by n-UV light in the range from 220 to 550 nm and shows a broad emission band centered at 520 nm with a full width at half maximum of 86 nm. The optimized doping concentration of Eu 2+ was determined to be 0.02 mol. With the increase of Eu 2+ content, a subtle red shift about 4 nm in emission spectra was detected. SZYP:Eu 2+ also shows comparable thermal stability (45% at 150 °C) and it can be further varied to 44, 40 and 51% by co-doping with Pr 3+ , Tm 3+ and Yb 3+ , respectively. The white LED device blended with SZYP:Eu 2+ shows excellent electroluminescence (EL) properties. The low correlated color temperature (4791 K) and ultrahigh color rendering index (95.8) imply that this phosphor may find a potential application in high-quality white LEDs.
研究领域:
材料科学
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光学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 27
·8226-8235
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IF 6.641
Xinxin Han,Enhai Song,Bo Zhou,Qinyuan Zhang
In contrast to simply static fluorescence, the introduction of time-resolved visualized fluorescence in materials can significantly improve their anti-counterfeiting performance; however, this remains challenging with photon upconversion (UC) luminescent materials. Herein, we demonstrate a color-tunable UC luminescent perovskite fluoride KCdF3:Yb3+,Mn2+,Ln3+ (Ln3+ = Er3+, Ho3+, Tm3+) with both long (∼20–40 ms) and short (∼0.4–2 ms) emission lifetimes. Under steady 980 nm laser excitation, color-tunable steady UC fluorescence from yellow to red (or green) and yellow to blue (including UC white emission) could be easily achieved by tuning the doping concentration of Mn2+ and Ln3+ in the system; whereas, an unalterable yellow UC afterglow was observed by the naked eye when the excitation source was removed. Moreover, the upconversion nanoparticles (UCNPs) exhibited excellent pump power- and temperature-dependent luminescence stability. Static and dynamic photoluminescence analysis provided an understanding of the unique UC luminescence in this system, and a bidirectional energy transfer UC mechanism between Mn2+ (or Yb3+–Mn2+ dimer) and Ln3+ is presented. The multiple anti-counterfeiting prototype using the unique UC luminescent materials demonstrated a high throughput authentication rate without the need for complex, time-gated decoding instrumentation, suggesting their high potential for anti-counterfeiting application, and also providing new insights for the design of photon UC luminescence materials.
研究领域:
材料科学
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光学
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光子学
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化学
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防伪技术
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产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 7
·期 1
·168-182
·
IF 8.683
Peiran Huang,Zuhui Wen,Yue Yu,Jingyi Xiao,Zhanhua Wei,Tianshuai Lyu
X-Ray or 254 nm UV-light charged storage phosphors have various promising applications such as in anti-counterfeiting and information storage. However, developing such storage phosphors with high charge carrier storage capacity remains challenging. In this work, photoluminescence spectroscopy, thermoluminescence (TL), and vacuum-referred binding energy (VRBE) diagram were combined to study the trapping and liberation processes of charge carriers in Bi3+ and/or Ln3+ (Ln = Tb, Pr, or Dy) doped LiLuGeO4. Unintended defects act as good electron trapping centers, while Bi3+, Tb3+, and Pr3+ act as hole-capturing and recombination centers. Dy3+ does not act as an electron trapping center but as a luminescence center by energy transfer from Bi3+ → Dy3+. The ratios of the integrated TL intensities between 303 K and 650 K for LiLuGeO4:0.005Bi3+, LiLuGeO4:0.005Bi3+,0.005Tb3+, or LiLuGeO4:0.005Bi3+,0.005Dy3+ after X-ray charging to that of the state-of-the-art BaFBr(I):Eu2+ is about 1.24, 0.59, and 0.90, respectively. More than 10 h or 40 h afterglow was measurable in both LiLuGeO4:0.005Bi3+ and LiLuGeO4:0.005Bi3+,0.005Tb3+ after X-ray or 254 nm UV-light charging. The stored charge carriers stored can be efficiently excited to produce optically stimulated luminescence with a wide range 365 nm UV-light to 850 nm infrared laser beam. Proof-of-concept colour-tailorable afterglow, X-ray irradiation time or sample mass-dependent dosimetry, and optically-stimulated luminescence with a wide range of 365 nm UV-light to 850 nm infrared laser stimulation will be demonstrated for anti-counterfeiting, information storage, and display applications in the developed Bi3+ and/or Ln3+-doped LiLuGeO4. This work not only reports Bi3+ and/or Ln3+ doped LiLuGeO4 storage phosphors with excellent charge carrier storage capacity but also deepens our understanding of the afterglow and storage phosphors and luminescence mechanisms, which can guide us to explore new afterglow and storage phosphors for multimode applications.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Mengran Ouyang,Huimin Du,Jiahao Wu,Shanshan Hu,Jun Yang
KSrGd(PO 4 ) 2 :Ln 3+ (Ln = Ce, Sm, Eu, Tb, Dy, Dy/Eu, Yb/Ho, Yb/Er, Yb/Tm) phosphors were synthesized by high temperature solid state method. Doping the KSrGd(PO 4 ) 2 matrix with 5%Dy 3+ ions resulted in white light emission under 345 nm excitation. The calculated color temperature (CCT) of this white light is 5523 K, indicating as positive white light. It was found that the luminous intensity of the obtained KSrGd(PO 4 ) 2 :5%Dy 3+ at 200 °C was 76.80 % of that at room temperature, showing good thermal stability as well as possibility of application in white LED. Under the excitation at 392 nm, the fluorescence quantum yield of KSrGd(PO 4 ) 2 :10%Eu 3+ is 79.92 %. Energy transfer between Dy 3+ and Eu 3+ is observed in KSrGd(PO 4 ) 2 :Dy 3+ /Eu 3+ samples, with identified mechanism as the quadrupole-quadrupole interaction. Tunable luminescence ranging from white to yellow then to orange-red is achieved by adjusting the doping concentration of Eu 3+ in KSrGd(PO 4 ) 2 :5%Dy 3+ , x%Eu 3+ . Under the excitation of 980 nm near-infrared light, the prepared KSrGd(PO 4 ) 2 :Yb 3+ /Ho 3+ , KSrGd(PO 4 ) 2 :Yb 3+ /Er 3+ and KSrGd(PO 4 ) 2 :Yb 3+ /Tm 3+ samples showed up-conversion emissions of red, yellow and blue, respectively, with two-photon processes. In KSrGd(PO 4 ) 2 matrix, multi-color and multi-security marks were successfully prepared by utilizing up/down conversion luminescence characteristics, which obtained good anti-counterfeiting effect and improved anti-counterfeiting security. Therefore, the obtained KSrGd(PO 4 ) 2 : Ln 3+ phosphors exhibit promising application prospects in the fields of WLED and multiple anti-counterfeiting.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）