CHEMICAL PHYSICS
·
2024
·
IF 2
Qian Du,Yu-Guo Yang,Xiao-Na Shen,Yuan-Yuan Zhang,Shen-Ao Hu,Bing Liu,Qing-Gang Li,Xian-Shun Lv,Hua-Jian Yu,Lei Wei,Cheng-Cheng Qiu,Jing-Feng Li,Rui Zhang,Xu-Ping Wang
Sr(La, Y)Ga 3 O 7 : Mn 4+ phosphors were prepared by sintering at 1400 ℃. The structural characteristics of phosphors were analyzed by means of XRD measurements. Surface compositions and chemical state of the elements were gained from XPS measurements. And the vibration and rotation information of the molecular structure was detected in Raman spectra. The phosphors show characteristic excitation spectrum of Mn 4+ , which puts down to the electronic transition of 4 A 2g → 4 T 1g and 4 A 2g → 4 T 2g . Exciting at 380 nm, the phosphors emit deep red light resulting from the 2 E g → 4 A 2g transition. The Y 3+ substitution influences crystal structure and photoluminescence performance obviously. The incorporation of a small amount of Y 3+ reduces the cell volume and induces impurity phase of Y 3 Ga 5 O 12 in all prepared phosphors. The band peaking at 715 nm decreases highly and the band becomes stronger when x ≥ 0.4.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Junshan Hu,Daobin Zhu,Keyu Guo,Bin Duan,Yuxiang Wu,Yongqiang Li,Fengyi Wang,Wei Jin,Changchun Ding
The KYb(MoO 4 ) 2 : Er 3+ , Y 3+ phosphors were synthesized by high temperature solid state reaction method. By further doping Y 3+ ions, the near-infrared (NIR, 804 nm, 4 I 9/2 → 4 I 15/2 ) luminescence of KYb(MoO 4 ) 2 : 0.1 % Er 3+ phosphor is greatly enhanced. Based on the upconversion luminescence (UCL) spectra, the optimal doping concentration of Y 3+ ions were 7.5 %. Its near-infrared UCL intensity is about 26.9 times that of undoped Y 3+ ions. Through a series of characterization methods, we find that the enhancement of NIR upconversion emission is due to the generation of defect bands. It plays a crucial role in facilitating the transfer of energy from green light level ( 2 H 11/2 , 4 S 3/2 ) to red light level ( 4 F 9/2 ) and near-infrared level. To explain the luminescence mechanism, the power dependence, UV-VI-NIR absorption spectra , excitation spectra at 804 nm and emission spectra at 380 nm were studied. In addition, the 804 nm single near-infrared UCL intensity of KYb (MoO 4 ) 2 : Er 3+ , Y 3+ shows a linear variation with temperature in the temperature range of 298 K–673 K. The maximum sensitivity is 0.13 % K −1 . This study provides a new method and theoretical support for the application of near-infrared UCL in optical temperature measurement.
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
·
2025
·
IF 4.2
Feihong Yang,Weiwei Li,Peng Luo,Jing Cheng,Laiming Chen
Transparent Yb:CaF 2 ceramics have recently emerged as a promising ultra-fast laser medium with broad emission bandwidth, long lifetime and suitable thermal properties. However, Yb 3+ clustering in the CaF 2 host strongly influences the performance of these materials as solid-state laser gain media, and mitigating this clustering remains a challenge. Herein, we introduced Y 3+ and Gd 3+ buffer ions simultaneously for the first time to modulate the fluorescence properties of transparent Yb:CaF 2 ceramics and explore the effect of Y 3+ and Gd 3+ ions co-doping on the optical quality and microstructure of the ceramics. It was found that transmittance in the short wavelength was improved and fluorescence properties could be modulated to a larger extent compared to single buffer ion doping. This finding establishes the correlation between the double buffer ions doping and the fluorescence properties in transparent Yb:CaF 2 ceramics, and may lead to innovative techniques of transmitting enhancement, as well as its ultrafast laser applications.
研究领域:
材料科学
·
光学材料
·
固体激光器
·
陶瓷材料
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Chao Hu,Lan Luo,Rui Guo,Ziying Ma,Ye Liu
Mn 4+ -active far-red emitting garnet phosphors are attractive in plant cultivation for chemical/physical stability and emission band well matching with the phytochrome absorption. (La 1-x Y x ) 3 Li 5 Sb 2 O 12 : Mn 4+ (x = 0∼0.4) garnet phosphors were fabricated by solid-state reaction in this work. The powder could exhibit far-red emission centered around 717 nm (related to Mn 4+ 2 E g → 4 A 2g transition), with the highest luminescence quantum efficiency ( QE ) and thermal quenching temperature ( T 0 . 5 ) reaching 38.03 % and 520 K, respectively. Comparing with La 3 Li 5 Sb 2 O 12 :Mn 4+ , the properties have been improved significantly, with double in QE and 20 K higher in T 0.5 . Y 3+ cation substitution would lead a stronger crystal field (verified by D q /B calculation) and a less spin-orbit coupling (verified by EPR spectra), and result in a smaller energy splitting and centroid shifting in 2 E g level. Then the luminescent efficiency and thermal stability would be improved a lot. The work not only provides a new far-red-emitting phosphor but also offers a strategy for Mn 4+ -active luminescence material improvement.
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Lingfeng Shi,Ziwei Liu,Ke Li,Yanbin Ning,Shengwei Dong,Shenglu Geng,Mengjie Zhang,Yulin Ma,Geping Yin,Zhenjiang Yu,Shuaifeng Lou,Hua Huo
O3-NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathodes are promising candidates for sodium-ion batteries benefited of the high theoretical capacity. However, the inherently poor electronic conductivity limits rate performance and aggravates O3-P3 phase transition, further weakens phase transition reversibility and results in structural degradation. Herein, a localized electronic regulation strategy inspired by yttrium iron garnet (YIG) is employed to address the issue of sluggish electron transport. Specifically, Y 3+ ions are utilized to partially substitute Ni 2+ to rearrange the electronic configuration of Fe 3 d orbitals, which could trigger a transition from high-spin state ( t 2 g 3 e g 2 ) to low-spin state ( t 2 g 5 e g 0 ) as well as narrow the band gap due to the asymmetric splitting of the t 2 g ∗ band near the Fermi level. Moreover, the large ionic radius tends to construct a concentration gradient of Y 3+ , thereby generating a long-range built-in electric field. Benefiting from the improved electrical conductivity, Y0.25-NFM performs 64 mAh g −1 reversible capacity at 20 C, also the enhanced reversible phase transitions assist Y0.25-NFM maintains 80.9% of initial capacity at 1 C for 500 cycles (44.7% for baseline NFM). The thorough understanding of the dual regulatory effects for Y 3+ doping on short & long-range electronic interactions provides a novel strategy to construct outstanding layered oxide cathodes for advanced SIBs.
研究领域:
材料科学
·
电化学
·
储能技术
·
固态物理
✓ 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）