Advanced Optical Materials
·
2024
·
IF 8
Qiaoling Chen,Litian Lin,Chang Ji,Chang-Kui Duan
The unintentional incorporation of various unknown trace amounts of impurities poses challenges and controversies in identifying luminescent mechanisms of certain systems. A common approach to confirm or exclude the involvement of a certain activation center is to monitor the changes in luminescence by intentionally doping the inferred species into the crystal. Here, an intriguing luminescent phenomenon resulting from the hidden interplay between the dopants and trace impurities, is presented. In alkaline-earth stannate perovskites, near-infrared luminescence is observed. By combining density-functional calculations with the well-designed doping and codoping experimental strategies, the mechanisms behind this anomaly is successfully uncovered. It originates from the stabilization of Cr 3 + by codopants such as Bi and rare-earth (RE) ions, acting as electron donors. The luminescence is almost unobservable when chromium is doped alone, and thus the traditional identification method does't work. This work emphasizes the important role of trace impurity in materials, especially the subtle change of valence state of trace impurity upon doping, which provides enlightening insights and prompts reassessments of numerous reported anomalous luminescent phenomena.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Yihao Xu,Li Luo,Weiren Zhao,Wei Zhang,ZhengFa Hu
Developing novel broadband near-infrared (NIR) phosphors is crucial to promote NIR phosphor-converted light emitting diodes (pc-LEDs) development. In this paper, a novel multifunctional near-infrared phosphor, SrGa 4 O 7 :Cr 3+ , Yb 3+ , was synthesized by the conventional high-temperature solid-state method. The emission band of the material spans from 650 nm to 1100 nm. Despite the predominance of four-coordinate and five-coordinate sites within the SrGa 4 O 7 (SGO) lattice, the incorporation of Cr 3+ ions induces distortion in the Ga–O tetrahedra, resulting in an octahedral environment for Cr 3+ . Under blue light excitation, the Cr 3+ ions exhibit an ultra-wide emission band (650–900 nm) with a Full Width at Half Maximum (FWHM) of 131 nm. Furthermore, energy transfer from Cr 3+ to Yb 3+ was achieved in SrGa 4 O 7 :Cr 3+ , Yb 3+ , and the incorporation of an optimal quantity of Yb 3+ co-dopant yielded a significantly enhanced and extraordinarily broad spectrum from 600 to 1100 nm. Moreover, Yb 3+ -codoping improves the thermal stability due to the energy transfer from Cr 3+ to more thermally stable Yb 3+ emitters, and the integrated intensity of SrGa 4 O 7 :Cr 3+ , Yb 3+ at 300 K was 74% of that at room temperature. Based on these findings, a blue-light-excited NIR pc-LED was encapsulated. The forward voltage and intensity of the LED remained almost constant after 500 h of thermal aging at high temperatures, indicating its particular reliability in NIR pc-LED applications. The results show that SrGa 4 O 7 :Cr 3+ , Yb 3+ phosphors have great potential in ultra-wideband NIR pc-LED applications.
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
Zhiwei Xia,Lan Yao,Xin Pan,Ke Su,Rujun Yang,Yuanhao Jian,Rong-Jun Xie,Lefu Mei
The development of efficient dual-emissive and temperature-sensitive luminescent materials is critical for advancing non-contact optical thermometry. Herein, we employed a co-doping strategy to enhance energy transfer pathways in Ca 9 Ga(PO 4 ) 7 phosphors. Under 331 nm excitation, dual emissions from Eu 2+ (415 nm) and Cr 3+ (696 nm) were achieved, with Zn 2+ enhancing the near-infrared (NIR) of Cr 3+ . The optimal Cr 3+ concentration led to an approximately six-fold increase in NIR emission intensity, attributed to Eu 2+ -induced crystal field modulation and efficient dipole-dipole energy transfer, which are evidenced by comparing the emission spectra and decay curve lifetimes. Temperature-dependent emission spectra revealed that Eu 2+ emission remained stable, while Cr 3+ emission exhibited significant temperature sensitivity in Ca 9 Ga(PO 4 ) 7 :Zn 2+ ,Eu 2+ ,Cr 3+ , enabling precise temperature sensing with a peak sensitivity of 1.256 % K −1 at 298 K. This work offers a novel approach to improving energy transfer efficiency and dual-emission properties, contributing to the development of high-performance, real-time optical thermometry and photonic technologies.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2016
·
IF 3.997
Xinjian Cheng,Yun Yu,Yiru Jia,Lian Duan
Three small molecular boron dipyrromethene (BODIPY) derivatives (B3a, B3b and B3c) were well-designed and synthesized at first, and then were incorporated into polyurethane to obtain macromolecular fluorescent sensors. These small molecular BODIPY derivatives exhibited high sensitivity and selectivity to Hg 2 + , Cr 3 + and Fe 3 + ions. The colors of these chemicals changed rapidly upon the addition of Hg 2 + , Cr 3 + and Fe 3 + ions. In addition, their fluorescence peaks shifted and was enhanced as well. B3a, B3b and B3c still remained the sensing properties when being introduced to polyurethane (PU). The functionalized PU films not only showed color change and fluorescence shift for detecting Hg 2 + , Cr 3 + and Fe 3 + ions as their small molecular counterparts, but also triggered a new emission peak in 500–600 nm. Besides, the functionalized PU film (PU-B3a as a sample) could absorb Hg 2 + ions more than 84 mg/g in unit time and volume. It suggested that as long as the structure of the small molecular sensor was remained, the fluorescent ability remained even it is introduced to the macromolecular chains. In addition, Glass transition temperature (T g ) of the PU films changed when B3a, B3b and B3c were introduced.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Jiyou Zhong,Chaojie Li,Weiren Zhao,Shihai You,Jakoah Brgoch
Near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) technology has attracted considerable interest as a next-generation light source for emerging NIR spectroscopic applications. However, discovering efficient broadband NIR phosphors necessary to access the desired long-wavelength (λem ≥ 800 nm) energy window remains a challenge. Here, a new phosphate phosphor, KGaP2O7:Cr3+, emerged from a fundamental study of the AMP2O7 (A = Li, Na, K; M = Al, Ga, Sc, In) family. This material combines all of the requisite properties for the efficient generation of NIR photons, including limited defect formation, minimal electron–phonon coupling, a subtle octahedral site distortion, and well-separated transition metal substitution sites. Photoluminescence spectroscopy indicates that this material emits from 700 to 1100 nm (λmax = 815 nm) with a full width at half-maximum (fwhm) of 127 nm or 1874 cm–1. Exciting the material with a blue LED reveals a quantum yield of 74.4% with an absorption efficiency of 44.8%, resulting in an excellent external quantum efficiency as high as 33.3% from the as-prepared sample. A prototype NIR pc-LED device generated an output power of 473.8 mW and a high photoelectric conversion efficiency (10.7% under 500 mA), demonstrating the potential of applying this phosphor in blue LED-based NIR spectroscopy.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2018
·
IF 0
Zhejian Wu,Rong Chen,Qimao Gan,Jian Li,Tuqiao Zhang,Miaomiao Ye
Mesoporous Na + SiO 2 spheres with large surface areas, high porosities and tunable Na + contents have been synthesized by the Stöber method followed by the “polyvinylpyrrolidone (PVP)-protected NaOH etching” process. With the surface protection of PVP, the NaOH etching preferentially occurs inside the SiO 2 spheres results in the increase of the surface areas and porosities of the SiO 2 spheres while keeping the sphere size unchanged at the etching degree less than 50%. The surface area and pore volume of the selected Na + SiO 2 spheres with etching degree of 50% are 302.9 m 2 /g and 0.946 cm 3 /g, respectively, which are 31 times and 59 times higher than that of the SiO 2 spheres without NaOH etching. The Na + SiO 2 spheres with etching degree of 10% calcined at 400 °C shows high adsorption activity for Cr 3+ removal from different natural waters such as tap water, lake water and river water. The adsorption kinetic of Cr 3+ by the Na + SiO 2 spheres fits well with the pseudo-second-order model, and the adsorption isotherm can be fitted by the Langmuir adsorption isotherm. The maximum adsorption capacity of 10% Na + SiO 2 400 for Cr 3+ is 33.18 mg/g. Finally, it has been confirmed that the ion-exchange between Na + and Cr 3+ plays the leading role in the adsorption process while the contribution from static adsorption is relatively weak.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
MATERIALS LETTERS
·
2023
·
IF 3
Changhai Zhang,Guoqiang Yi,Zaichun Sun,Bingchu Mei
Cr 3+ has attracted much attention as activator because of the merits such as, broadband near-infrared emission and tunable emission wavelength. However, the mixed valence of Cr 3+ in some matrix materials greatly affected its luminescence. In this work, we synthesized Cr 3+ doped CaF 2 (CaF 2 :Cr 3+ ) precursor powders with a single valence of Cr 3+ ion by coprecipitation and successfully prepared CaF 2 :Cr 3+ transparent ceramics by vacuum hot-press sintering. The obtained ceramics showed high transmittance with 83% at 1200 nm and effective broadband near-infrared emission covering 680–980 nm with a full width at half-maximum (FWHM) of 130 nm. Moreover, the photoluminescence properties of ceramics were tuned by the concentration of Cr 3+ ions.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 27
·21290-21296
·
IF 3.84
Fanpeng Cai,Yubin Tang,Fangyan Chen,Yan Yan,Weidong Shi
The removal of tetracyclines (TC), the extensively used antibiotics, from the environment has become an important issue. Recently, photocatalytic oxidation on the surface of semiconductors has been found to provide a good tool for the degradation of TC; however, most of these reactions are UV-light driven rather than visible-light driven. Here, Cr doping of SrTiO3 results in a large decrease in the band gap energy, making Cr3+ doped SrTiO3 (Cr-STO) an attractive material for use as a visible-light-driven photocatalyst for tetracycline (TC) degradation. The photoactivity is improved when the Cr/Sr weight ratio changes from 0.5% to 2%, and decreases when the Cr/Sr weight ratio changes from 3% to 10%. In this paper, we also explain the relationship between the doping and the photocatalytic activity. The existence of ˙OH radicals and holes was studied by the electron spin resonance (ESR) spin-trap technique and trapping experiments.
研究领域:
环境科学
·
材料科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jinqiang Wang,Zhaoyang Su,Nigel J.D. Graham,Hongkai Liu,Kai Sun,Wenzheng Yu
This paper focuses on the functionalization of double positively charged polyethylenimine (PEI)/Zr 4+ -polyamide (PA) nanofiltration (NF) membrane by connecting Zr 4+ with positively charged PEI-PA NF membrane surface. In particular, the properties of prepared PEI/Zr 4+ -PA NF membrane, performance on removing aquatic contaminants (Cr 3+ and trimethoprim), and its antifouling ability were evaluated in detail. In this regard, zirconium acetate was successfully adopted as the zirconium source for stable membrane surface charge control. Zr 4+ loading increased the hydrophilicity of the PEI-PA NF membrane, improved permeate flux, and enhanced the removal behavior of PEI/Zr 4+ -PA NF membrane especially when exposed to Cr 3+ and trimethoprim at high concentrations. Furthermore, effectiveness of PEI/Zr 4+ -PA NF membrane was not affected by high filtering degree, filtration cycle, and negatively charged macromolecules, such as bovine serum albumin (BSA). Also, antifouling ability of PEI/Zr 4+ -PA NF membrane could be further improved by continuously loading Zr 4+ .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
·
2025
·
IF 7.2
Ou Xu,Xiaoyan Lu,Xiaodong Shen,Tongzhou Li,Bao Ke,Jialong Zhao,Bingsuo Zou
CsPbBr 3 nanocrystals (NCs) have attracted extensive attention due to their high color purity and good thermal stability. However, due to the quenching of surface defects, the photoluminescence quantum yields (PLQY) are low, and there are few previous comparative studies on the magnetic ion doping of powders and nanocrystals in this system. In this article, the effect of Cr 3+ doping CsPbBr 3 NCs and CsPbBr 3 powders and their PL properties is investigated. The successful doping of Cr 3+ is verified by TEM, SEM, and EDS characterization. At the appropriate amount of Cr 3+ , the PLQY of Cr 3+ doped CsPbBr 3 NCs achieves 96%, twice that of undoped CsPbBr 3 NCs. However, the PLQY of the CsPbBr 3 powder does not change much after Cr 3+ doping at its close emission wavelength. The electron paramagnetic resonance (EPR), temperature dependent PL and density functional theory (DFT) calculation show that the enhanced PL of doped CsPbBr 3 NCs is due to the formation of exciton magnetic polaron (EMPs), while the confined excitons in undoped NCs are multiple due to spin-orbit interaction. In CsPbBr 3 powders, both EMPs and antiferromagnetic excitons (AMPs) coexist and compete, verified by the PL decay curve, temperature variation spectra, and low temperature PL spectra in strong magnetic field.
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 THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 9
·4577-4584
·
IF 3.784
Tianyao Liu,Hao Cai,Ning Mao,Zhen Song,Quanlin Liu
Broadband near-infrared phosphors are essential to realize nondestructive analysis in food industry and biomedical areas. Efficient long-wavelength (>830 nm) phosphors are strongly desired for practical applications. Herein, we demonstrate an efficient broadband NIR phosphor LiInGe 2 O 6 :Cr 3+ , which exhibits a broad NIR emission peaking at ~880 nm with a full width at half maximum of 172 nm upon 460 nm excitation. The internal/external quantum efficiencies of LiInGe 2 O 6 :Cr 3+ are measured to be 81.2% and 39.8%, respectively. The absorption of the phosphor matches well with commercial blue LEDs. Using the fabricated phosphor converted LED illuminating human palm, distribution of blood vessels can be clearly recognized under a NIR camera. These results indicate that LiInGe 2 O 6 :Cr 3+ is a promising candidate to be used in future non-destructive biological applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Yibiao Ma,Weifang Liao,Beibei Quan,Zihui Kong,Maxim S. Molokeev,Andrey Zolotov,Ming Cheng,Xiaoyan Chen,Zhi Zhou,Mao Xia
Lead-free non-rare earth oxide phosphors have attracted wide attention due to their environmental protection, sustainability, and potential to replace halides and fluorides in the field of plant lighting. Among them, the Cr 3+ -excited aluminate phosphor exhibits high brightness, high thermal stability, and far red to near-infrared (NIR) emission due to the influence of the crystal field strength (CFS). This property gives rise to a variety of strategies used to modulate the CFS, for example, single ion substitution, chemical unit co-substitution, etc. Here, we chose the substitution of a single ion, with [BaO6] gradually replacing [SrO6] to form a solid solution. Their structural characteristics and the local structure of Cr 3+ are studied and discussed. The device is packaged to evaluate the feasibility of the material for practical application. The prepared phosphor had a bright far-red light emission of 693 nm under blue light excitation, and this spectrum strongly matched the absorption of plant phytochrome P FR . This work provides the design principle of far red light emission activated by Cr 3+ aluminate solid solution, which can inspire further research on pc-LED lights for plant lighting.
研究领域:
材料科学
·
植物学
✓ 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）