OPTICAL MATERIALS
·
2020
·
IF 2.779
Shichang Xu,Jianjun Duan,Peipei Dong,Muyao Wang,Yanjie Zhang,Jingjie Yu
A series of Eu 2+ activated Ca 10 (PO 4 ) 6 Cl 2 phosphors (ClAp: Eu 2+ ) with enhanced blue emission have been prepared by the deposition precipitation (DP) process. The XRD patterns indicate that Eu 2+ ions are incorporated into Ca 10 (PO 4 ) 6 Cl 2 lattice during the DP process. The ClAp: xEu 2+ -DP phosphor exhibits an super broad excitation band of 250 nm–420 nm consisting of three distinct peaks at 276 nm, 343 nm and 365 nm, ascribed to the 4f 6 → 4f 7 5 d 1 transition of Eu 2+ ions in 4f and 6 h sites. Under 350 nm excitation, ClAp: xEu 2+ -DP phosphors show the intense blue emission at 453 nm and the maximum intensity is obtained when x = 0.3. Notably, an enhanced blue emission intensity of ~2.1 times can be found for ClAp:0.3Eu 2+ -DP phosphor compared with the sample prepared by traditional solid state reaction (SSR) method. Further, the EDX elemental mapping of the phosphor demonstrates that DP process can effectively promote the uniform distribution of Eu 2+ ions on the surface of ClAp crystal and avoid the aggregating problem of activators in SSR method, which can greatly improves the photoluminescence property. It can be concluded from HRTEM images and decay curves that ClAp:0.3Eu 2+ -DP phosphor exhibits characteristic lattice fringes similar to those of ClAp:0.3Eu 2+ -SSR phosphor, but a longer average decay lifetime (392 ns). In addition, the presence of trivalent europium ions on the surface of ClAp: 0.3Eu 2+ -SSR and ClAp: 0.3Eu 2+ -DP phosphors can be identified by XPS analysis . All the results reveal that DP process is an efficient way to prepare highly dispersed Eu 2+ activators in Ca 10 (PO 4 ) 6 Cl 2 host and the ClAp: Eu 2+ -DP phosphors can be the promising candidate for blue emission in white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Zhenggang Zou,Jiawei Zhu,Fulin Lin,Yijian Sun,Jianhui Huang,Jinsheng Liao,Guoliang Gong,Herui Wen
The development of Eu 2+ -activated oxide materials with high efficiency, fast decay and narrow bandwidth emission in the visible region is still challenging for the field of luminescence and scintillation applications. Generally, Eu 2+ in oxide hosts can emit intense and broad 5d-4f emission in the visible region, but efficient emitting with stable bivalence of Eu is rare in inorganic oxide system. In this work, a series of ASL:Eu 2+ (Sr 1-x La x Mg x Al 12-x O 19 ) powder samples with various La, Mg doping ratios were designed and synthesized to modulate the UV or X-ray excited luminescence properties , including redshift, quantum yield , and decaying lifetime. Moreover, an ASL:Eu 2+ crystal with the optimal ratio x = 1/3 was grown, its scintillation performance was compared with standard Bi 4 Ge 3 O 12 crystal sample and evaluated in detail. These results indicate that the ASL:Eu 2+ crystal is potential scintillator as a kind of X-ray detection and provide a reference for the further development of high-performance Eu-activated oxide scintillation materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Optical Materials Express
·
2022
·Vol. 12
·期 10
·4117-4132
·
IF 3.074
Zihan Zhao,Zihan Zhao,Ran Zhang,Ran Zhang,Hao Song,Yanjie Zhang,Yanjie Zhang,Yanjie Zhang,Xiuping Wu,Desheng Li,Bing Li,Bing Li
As blue emitting component in phosphor-converted white-light-emitting-diodes (pc-wLEDs) encapsulated with near-ultraviolet (NUV) chips, Eu2+ activated fluorapatite structure phosphors play key roles because of strong structural stability and excellent photoluminescent properties. A series of M5(PO4)3F: Eu2+ (M = Ca, Sr) samples have been newly prepared by deposition-precipitation process (DP) and exhibited a 6.7-fold enhancement of photoluminescent (PL) intensity due to the highly dispersed Eu2+ luminescence centers when compared with the reference samples synthesized via traditional solid-state reaction method (SSR). Detailed analysis of crystal field around Eu2+ and the nonlinear fitting of PL spectra concludes that Eu2+ activators with the 4f6 → 4f75d transition preferentially replace Ca1 in 4f symmetry sites leading to a fitted peak at 446 nm and the other sites of 6h are contributed to the 479 nm emitting of Eu2+ ions. Remarkably, tunable chromaticity of DP-M5(PO4)3F: Eu2+ with high color purity (97.79%) retains steady photoelectric converting and full width at half maxima (FWHM) of 46 nm in the device of DP-FAp: 0.03Eu2+@365 nm LED under diverse driving currents, which perfectly satisfies the requirements of excitation light source for oral photocuring materials. Further, the 123.4% color gamut of National Television System Committee (NTSC) standard is efficiently obtained by matching Sr5(PO4)3F: Eu2+, CsPbBr3 and Lu3Al5O12: Mn4+ phosphors with a 365 nm chip (1 W) to achieve high-quality white light (CRI value reaches to 86, CCT is 7107 K and CIE chromaticity coordinate arrives at (0.292, 0.376), indicating a potential candidate for dentistry curing light and high-quality NUV excited pc-wLEDs.
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 LUMINESCENCE
·
2025
·
IF 3.6
Zhichao Zhang,Jun Zhou,Jintai Wen,Fangnan Liang,Fang Zhang,Qianxiu Liu,Jifan Hu
Currently, data-driven methodologies for discovering advanced luminescent materials are receiving considerable focus, driven by the potential to expedite material development timelines and provide multi-faceted insights into material properties. This study implements machine learning to develop a predictive model for emission wavelengths in Eu 2+ -activated A I B II PO 4 -type phosphors, thereby advancing rational design strategies. Furthermore, the model's performance is rigorously evaluated by synthesizing a novel Na 18 Ca 13 Mg 5 (PO 4 ) 18 :Eu 2+ phosphor and comparing its emitting wavelength with the value predicted by the model, showing satisfactory agreement. The compound Na 18 Ca 13 Mg 5 (PO 4 ) 18 exhibits a glaserite-type crystal structure and belongs to the R-3m space group of the Trigonal crystal system. The Eu 2+ -activated Na 18 Ca 13 Mg 5 (PO 4 ) 18 phosphor demonstrates intense broadband absorption spanning 250–400 nm in the near-ultraviolet region, emitting bright blue-cyan luminescence under 365 nm excitation. The high Ra (93.3) and low correlated color temperature (CCT: 5096 K) values of the as-fabricated w-LED lamp indicate that Na 18 Ca 13 Mg 5 (PO 4 ) 18 :Eu 2+ can act as a promising blue-cyan-emitting phosphor for full-spectrum healthy lighting applications.
研究领域:
材料科学
·
机器学习
·
光电子学
·
固态照明
·
晶体学
·
发光材料
·
数据驱动发现
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 22
·8145-8152
·
IF 5.7
Dongkai Hu,Mavlanjan Rahman,Shuifu Liu,Lina Shen,Pengpeng Dai,Dawei Wen,Mingmei Wu
While numerous approaches have been devised to optimize the luminescence properties of Eu2+-activated phosphors, the quest for a simple design strategy to achieve color-tunable Eu2+ emission remains a significant challenge. Here, we present a straightforward, doping-free method to tailor the site occupation of Eu2+ and modify its luminescence properties. In the pristine sample, the NaBaB9O15 (NBB) host featuring two cation sites (Na+ and Ba2+), Eu2+ exclusively occupies the Ba2+ site, resulting in blue emission when the NBB:Eu2+ phosphor is synthesized in a H2 reducing atmosphere. When we use CO instead of a H2 reducing atmosphere, impressively, the formation energy required for heterovalent substitution of Na+ by Eu2+ is lowered, leading to the emergence of a distinct green emission band. Significantly, the resultant phosphor NBB:Eu2+@CO exhibits not only a high internal quantum yield of 85.1% and zero-thermal-quenching behavior within the temperature range of 25–200 °C but also wavelength-tunable emission. Benefitting from the multi-color luminescence of the NBB:Eu2+@CO phosphor, its optical applications will no longer be confined to general lighting but extend to anti-counterfeiting and encryption. This study provides a novel design methodology for optimizing the optical properties of Eu2+-activated phosphors.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）