MATERIALS LETTERS
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2025
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IF 2.7
Tingting Yan,Lei Sun,Dongyang Xi,Dinghan Jin,Han Li,Linan Liu
SrNb 2 O 6 and SrNb 2 O 6 :Ho 3+ red phosphors were successfully synthesized by a novel molten salt method. Compared with the traditional synthesis method, the reaction rate is faster at lower temperature. Scanning Electron Microscopy showed the samples are rod-like crystals with an average size of 5 μm. Upon excitation at 638 nm, the samples exhibited red emission peaks in the range of 640–680 nm, which are attributed to the Ho 3+ 5 F 5 → 5 I 8 electronic transition. As the concentration of Ho 3+ increases, the luminescence intensity gradually rises, peaking at x = 0.03. To explore the stability of the crystal structure under pressure, we conduct high-pressure Raman scattering experiments on SrNb 2 O 6 . Significant changes in the Raman spectra indicate a reversible phase transition between 3.1 and 5.4 GPa. Geometric optimization based on density functional theory suggest that the phase transitions originate from increased coordination of Sr atoms.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2020
·
IF 4.706
Yuzhen Sun,Huifang Bi,Tao Wang,Leilei Sun,Zexin Li,Haining Song,Fenglei Sun,Haifeng Zhou,Guangjun Zhou,Jifan Hu
NaYF 4 :10Er/0.5Ho/30Ca@NaYF 4 is designed to achieve up-conversion luminescence color adjustment under 980 nm excitation. Ho 3+ doping enhances the red emission level of the system and changes the characteristic green emission into red emission. Importantly, Ho 3+ doping increases the difference in pumping time between green and red excited states. Under short pulse-width laser excitation, the red excited state does not have enough time to be populated, which weakens the emission of red emission, and the ratio of green to red emission will change. It is an effective up-conversion luminescence enhancement method to change the symmetry of crystal field around lanthanide ions by doping Ca 2+ . The green and red emission intensities of NaYF 4 :10Er/0.5Ho/30Ca doped with 30% Ca 2+ ions are 9.0 and 6.3 times higher than those of Ca 2+ free samples, respectively.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Yiying Zhu,Guoxun Sun,Yining Wang,Yixin Sun,Xiaole Xing,Mengmeng Shang
Doping lanthanide ions is an efficient method to modify the optical properties of lead-free double-perovskite halides. However, most lanthanide-doped double perovskites show a low luminescence efficiency and require a high excitation energy. Here, we have successfully prepared a series of Ho3+-doped Cs2NaBiCl6 microcrystals through a simple hydrothermal method and obtained strong characteristic emissions of Ho3+ at 492 and 657 nm under low-energy excitation (449 nm). After codoping Mn2+, apart from the characteristic emissions from Ho3+ under 450 nm wavelength excitation, the orangish-red luminescence consisting of the emission band centered at 591 nm from Mn2+ and a sharp emission peak at 657 nm from Ho3+ is obtained under 355 nm UV light excitation. Photoluminescence (PL) emission and excitation spectra, along with the PL decay curves, confirm the existence of an energy-transfer channel from Cs2NaBiCl6 to Mn2+ and then from Mn2+ to Ho3+. The enhanced absorption efficiency (10.5 → 70.7%) suggests that the codoping of Mn2+ overcomes the low absorption efficiency caused by f–f forbidden transitions of Ho3+. Finally, the diverse luminescent performance within the Cs2NaBiCl6:Ho3+, Mn2+ phosphor is realized by altering the excitation wavelength, thereby enabling its application in warm-white-light-emitting diodes and plant growth in this work.
研究领域:
材料科学
·
光学工程
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2018
·Vol. 5
·期 6
·066106
·
IF 1.151
Renxin Xu,Huan Yang,Huajun Sun,Yueli Liu,Huan Zhou,Jianchun Liu
Mg0.2Mn0.8HoxFe2−xO4 (x = 0.025, 0.050, 0.075 and 0.100) nanocrystalline is synthesized via a hydrothermal technique. Single phase cubic spinel is confirmed by XRD and the formation of Mg0.2Mn0.8HoxFe2−xO4 is verified by EDS. The average size for the nanoferrites is around 80 nm which is examined by TEM with the presence of agglomerated particles. Ho3+ substituted Mg-Mn nanoferrites exhibit the low saturation magnetization (Ms) and coercivity (Hc). Especially, with x = 0.100, the nanoferrites show the lowest Ms and Hc of 46.850 emu g−1 and 46 Oe, respectively. The ferrite composites present the dielectric dissipation less than 0.37 and the magnetic loss less than 0.46 at 2–18 GHz. The low saturation magnetization, low coercivity and low dielectric dissipation indicate that the addition of Ho3+ contributes to synthesize better soft magnetic materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Yu Yin,Jie Chen,Rong Liu,Xiaodan Zeng,Wei Zhao,Zhigang Liu,Mingshuo Ma
Water-dispersed red upconversion nanoparticles (UCNPs) have great application prospects in the biomedical field. Thus, a series of Er 3+ -based upconversion nanoparticles (Er-UCNPs) with excellent red upconversion luminescence under three-wavelength NIR excitation (808/980/1550 nm) were prepared by a simple thermal decomposition method, and then further functionalized by PAA to achieve good water dispersibility. Compared with NaErF 4 bare core, the emission intensity of Er-UCNPs samples doping of 0.5%Tm 3+ and 0.5%Ho 3+ as energy capture centers was significantly enhanced, and further improved after coating with NaYF 4 inert shell. Meanwhile, among all Er-UCNPs@NaYF 4 samples, NaErF 4 @NaYF 4 exhibited the highest emission intensity and longest luminescence lifetime due to the efficient suppression of luminescence quenching effect, while NaErF 4 :0.5%Tm 3+ @NaYF 4 showed highest red luminescence purity owing to the energy transfer process between Tm 3+ ( 3 H 5 ) and Er 3+ ( 4 I 13/2 ). The hydrophilic Er-UCNPs@NaYF 4 @PAA samples still maintained good red luminescence under multi-wavelength excitation. The luminescence enhancement mechanism in Er-UCNPs@NaYF 4 was discussed in detail based on spectral characteristics. The as-prepared water-dispersed Er-UCNPs@NaYF 4 @PAA with bright red luminescence under multi-wavelength NIR excitation will have potential applications in targeted therapy and deep tissue imaging.
研究领域:
生物医学
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材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yanting Liu,Qiumei Li,Lili Meng,Qi Pang,Yanzhu Wang,Hua Yao,Qian Chen
Currently, lanthanide (Ln 3+ ) doped double perovskites (DPs) suffer from poor controllability of doping and the high concentration quenching phenomenon. Herein, a novel efficient energy transfer (ET) host of Cs 2 NaLuCl 6 Rare-earth-based (RE-based) DPs via Ag + /Bi 3+ co-doping for further Ho 3+ doping is developed. Benefiting from Ag + /Bi 3+ - manipulated the parity of the wavefunction of the self-trapped exciton, intense self-trapped excitons (STEs) broadband warm white visible emission is boosted. Specifically, photoluminescence quantum yield (PLQY) of co-doping with Bi 3+ and Ag + ions in Cs 2 NaLuCl 6 under 350 nm excitation is dramatically promoted to 86.19 % with half maximum (FWHM) of 224 nm. Although the pristine crystal Cs 2 NaLuCl 6 exhibits intrinsic blue emission with FWHM of 75 nm. Furthermore, the ET channel from STEs to Ho 3+ was constructed by tri-doping Ho 3+ , and the effective red and near-infrared (NIR) emission of Ho 3+ was obtained. Finally, NIR light-emitting diodes (LEDs) and white LED based on Ho 3+ doped/undoped Cs 2 Na 0.8 Ag 0.2 Lu 0.98 Bi 0.02 Cl 6 DPs were prepared with different application features. Specifically, white LEDs showed higher color rendering index and lower associated color temperature, while NIR LEDs showed good night vision imaging. This work provides a new strategy for the design of an ET host suitable for Ln 3+ doping, avoiding the effects of the concentration quenching phenomenon that always occurs in heavily doped hosts and realizing controllable doping.
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
Frontiers of Optoelectronics
·
2023
·Vol. 16
·期 1
·1-11
·
IF 5.4
Zhang Chuancheng,Ding Shoujun,Wang Miaomiao,Ren Hao,Tang Xubing,Zou Yong,Dou Renqin,Liu Wenpeng
Optical thermometry based on the upconversion (UC) luminescence intensity ratio (LIR) has attracted considerable attention because of its feasibility for achievement of accurate non-contact temperature measurement. Compared with traditional UC phosphors, optical thermometry based on UC single crystals can achieve faster response and higher sensitivity due to the stability and high thermal conductivity of the single crystals. In this study, a high-quality 5 at% Yb 3+ and 1 at% Ho 3+ co-doped Gd 0.74 Y 0.2 TaO 4 single crystal was grown by the Czochralski (Cz) method, and the structure of the as-grown crystal was characterized. Importantly, the UC luminescent properties and optical thermometry behaviors of this crystal were revealed. Under 980 nm wavelength excitation, green and red UC luminescence lines at 550 and 650 nm and corresponding to the 5 F 4 / 5 S 2 → 5 I 8 and 5 F 5 → 5 I 8 transitions of Ho 3+ , respectively, were observed. The green and red UC emissions involved a two-photon mechanism, as evidenced by the analysis of power-dependent UC emission spectra. The temperature-dependent UC emission spectra were measured in the temperature range of 330–660 K to assess the optical temperature sensing behavior. At 660 K, the maximum relative sensing sensitivity ( S r ) was determined to be 0.0037 K −1 . These results highlight the significant potential of Yb,Ho:GYTO single crystal for optical temperature sensors. Graphical abstract
研究领域:
光学材料
·
固体物理
·
发光光谱学
·
温度传感技术
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Yichen Ye,Yongbao Xiao,Yao Ji,Weichao Wang
Singly Ho 3+ -doped TeO 2 –Ta 2 O 5 –ZnO (TTZ) glass and optical fiber for 2 μm fiber lasers have been investigated. The glass-forming region of the ternary TTZ glass system is determined to study its glass-forming ability and to select an appropriate glass matrix for doping Ho 3+ ions. Upon the excitation of a 1940 nm laser diode (LD), an intense emission at 2.06 μm with a full width at half maximum (FWHM) of 61 nm is observed from the Ho 3+ -doped TTZ glass. The measured lifetime of the Ho 3+ : 5 I 7 level in TTZ glass shows a gradual decrease from 3.5 to 0.98 ms as the dopant concentrations increase from 0.2 to 2 mol%. A large emission cross-section (σ e MC ∼ 4.56 × 10 −21 cm 2 ) and figure of merit (FOM, ∼ 6.83 × 10 −24 cm 2 ·s) are obtained. The Ho 3+ -doped TTZ glass is further fabricated into an optical fiber with an average transmission loss of 0.12 dB/cm at 1310 nm. The results show that singly Ho 3+ -doped TTZ glass and optical fiber are promising candidates for efficient 2 μm fiber lasers.
研究领域:
光学
·
材料科学
·
光子学
✓ 已验证
DOI
高影响因子
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