JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yali Xue,Yujun Liang,Yi Dou,Haoran Li,Qiangke Wang,Xiaodeng Wu,Yongsheng Han
Reabsorption and color drift at high temperature hinder the high-quality application of the phosphor-converted white light-emitting diodes (pc-WLEDs) devices, thus it is urgent to develop the single-phase white-emitting phosphors with good chromatic stability. In this work, a series of color-tunable Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors are designed by co-doping Bi 3+ and Eu 3+ based on the crystal structure information and energy transfer principle between Bi 3+ and Eu 3+ , which can be adjusted to achieve single-phase white emission. By increasing the temperature to a high value of 473 K, the emission peak of Bi 3+ ions still present at 470 nm in Y 3 TaO 7 :Bi 3+ phosphors even when the concentration of Bi 3+ ions changes, and the characteristic emission peaks of Bi 3+ and Eu 3+ basically maintain unchanged throughout in Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors. Finally, the single-phased Y 3 TaO 7 :0.025Bi 3+ , 0.06Eu 3+ phosphor was employed with ultraviolet chip to produce a warm WLED device with color rendering index of 81.5, correlated color temperature of 4165 K and the Commission International de I′Eclairage chromaticity coordinates of (0.3645, 0.3347). The results indicate that Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors with high chromaticity stability have great application potential in full-spectrum 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
OPTICAL MATERIALS
·
2024
·
IF 3.8
Sihan Yang,Xuyan Xue,Ziying Wang,Qi Zhu,Xuejiao Wang,Ji-Guang Li
In this work, a series of broad-band green phosphors SrLaScO 4 : x Bi 3+ ( x = 0–0.1) were synthesized using the traditional solid-state method, and the luminescence was effectively enhanced via multi cationic partial substitution strategy. The SrLaScO 4 : x Bi 3+ phosphors all exhibit a wide emission band with a full width at half-maximum (FWHM) of 115–148 nm in the range of 450–700 nm upon excitation at 333 nm, effectively filling the cyan gap and peaking at 505 nm. It is proved that the observed luminescence originates from both the 3 P 1 state of Bi 3+ in [(Sr/La)O 8 ] site and the Bi 3+ - to - Sc 3+ metal to metal charge transfer (MMCT) state. The optimal concentration of Bi 3+ doped SrLaScO 4 phosphor is 1 at%, and the concentration quenching mechanism is the dipole-dipole interaction. Remarkably, the luminescence intensity of the phosphor is 198.4 % increased by partially replacing Sr 2+ ions with Mg 2+ . Due to the good matching of the excitation wavelength of the phosphor with the near-UV chip, a high-quality WLED device with color stability and high color rendering index ( Ra = 92.1) was prepared by combining commercial phosphor with SrLaScO 4 :0.01Bi 3+ phosphor. We anticipate that this work can provide new ideas for finding high-performance phosphors for high color rendering index pc-WLED.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS
·
2024
·
IF 2
Xuan Gu,Zheng He,Xao-Yu Sun
Eu 2+ -doped Sr 2 LaGaO 5 phosphors were prepared using a high-temperature solid-state route in a furnace at 1450 °C. Their phase, microstructure, and luminescent performance were thoroughly investigated. The XRD measurements indicate that the prepared phosphors exhibit a tetragonal phase. Upon excitation at 450 nm, the Sr 2 LaGaO 5 :Eu 2+ phosphors demonstrate a broad red emission ranging from 475 to 850 nm, with a peak at 620 nm. At a doping concentration of 6 %mol Eu 2+ , the phosphors exhibit the highest emission intensity, characterized by CIE coordinates of (0.536, 0.453) and a color purity of 65.53 %. The temperature-dependent emission analysis reveals that the phosphors possess excellent thermal stability. The emission intensity of the Sr 2 LaGaO 5 :0.06Eu 2+ phosphor at 420 K is about 53.9 % of the initial intensity measured at 300 K, with a thermal activation energy of 0.393 eV. The pc-WLED device was constructed via the combination of an LED chip, yellow Y 3 Al 5 O 12 :Ce 3+ and the prepared Sr 2 LaGaO 5 :Eu 2+ phosphors, resulting in the emission of warm white light with a CCT value of 4985 K.
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
·
2025
·
IF 5.6
Fang Fang,Yuanhao Chen,Boyan Liu,Xiaoshan Zhang,Benchun Li,Dawei Zhang,Dechao Yu
Red-emitting phosphors efficiently excited by near-ultraviolet (NUV) light are desired for high-quality phosphor-converted white LED (pc-WLED) devices. In this work, Eu 3+ /Tb 3+ codoped NaBiF 4 phosphors were designed as promising NUV-excitable candidates for the red component in pc-WLEDs. Under 379 and 395 nm excitation, the NaBiF 4 :Eu 3+ ,Tb 3+ samples yield intense red emissions, predominantly at 616 nm due to the 5 D 0 → 7 F 2 transition of the Eu 3+ ion. The Tb 3+ dopants bring in synergistic effects in greatly enhancing the Eu 3+ red luminescence, i.e. resonant energy transfer (ET) from Tb 3+ to Eu 3+ and crystal field perturbation surrounding Eu 3+ . The relevant spectroscopic properties were systematically studied using steady-state and time-resolved fluorescence spectroscopy. The optimized NaBiF 4 :20%Eu 3+ ,15%Tb 3+ sample features a nearly complete Tb 3+ → Eu 3+ ET, leading to a pure Eu 3+ red luminescence, and showing quantum yield values of 44.2% and 51.6% upon 379 and 395 nm excitation, respectively. Notably, the red luminescence from the NaBiF 4 :20%Eu 3+ ,15%Tb 3+ system has a high thermal stability, which at 398 K sustains 80.2% of its room-temperature luminescence intensity under 395 nm excitation. Via coating a mixture of commercial BaMgAl 10 O 17 :Eu 2+ blue- and (Ba,Sr) 2 SiO 4 :Eu 2+ green-emitting phosphors and the optimized phosphor on NUV ∼ 380 and 395 nm LED chips, the homemade 395 nm-excited pc-WLED exhibited interesting warm lighting performance, i.e. color rendering index (Ra) ∼ 90 and correlated color temperature (Tc) ∼ 3884 K, while the 380 nm-excited pc-WLED had Ra ∼88 and Tc ∼ 4685 K. That is, the NUV ∼395 nm chip (illumination also overlapping with the Tb 3+ absorption around 380 nm) is practically preferable to excite the Tb 3+ /Eu 3+ pc-LED for high-qualified warm white lighting. All the results unveil the viable schemes to develop the Eu 3+ /Tb 3+ co-activated red-emitting phosphors, offering promising prospects for novel NUV-excitable pc-WLED light sources.
研究领域:
材料科学
·
光学材料
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光子学
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固态照明
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发光光谱学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2026
·Vol. 109
·期 2
·e70588
·
IF 4.2
Xingbo Kang,Fan Li,Zhiyuan Pan,Qi Zhu,Ji-Guang Li
Without using any organic additive, zircon-type (space group I 4 1 / amd ) (Lu 1− x Sc x ) 0.99 VO 4 :0.01Bi 3+ ( x = 0−1, 0.1 interval) nano/microcrystals were successfully synthesized via a hydrothermal reaction at 180°C for 24 h. The products were systematically characterized via XRD, FE-SEM, TEM, elemental mapping, and optical spectroscopy to investigate the effects of Sc 3+ doping on crystal structure, morphology, and luminescent properties. It was found that with the substitution of Lu 3+ by Sc 3+ , the products gradually transformed from LuVO 4 :Bi 3+ nanocrystals into highly anisotropic ScVO 4 :Bi 3+ microrods preferentially growing up along the [001] direction. The peak wavelength of both excitation and emission almost linearly increased with decreasing cell volume, accompanied by band broadening, which was rationalized by considering crystal field splitting energy ( D q), character of the chemical bond (nephelauxetic effect) and metal to metal charge transfer (MMCT) energy. This finely tunable broadband emission (center wavelength 581−639 nm, FWHM >175 nm) enables the materials to supplement multicolor components, presenting potential for application in phosphor-converted white light-emitting diode (pc-WLED) and others.
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Liang Dong,Ziying Wang,Sihan Yang,Qi Zhu,Ji-Guang Li,Xuejiao Wang
Phosphor-converted white light-emitting diode (pc-WLED) is crucial for solid-state lighting, but the color rendering index of commercial pc-WLED needs to be improved. In this study, a series of silicates KSrScSi 2 O 7 : x Ce 3+ ( x= 0-10at%) were synthesized. Under the 365 nm near-ultraviolet excitation, the silicate emits a high-quality broadband cyan-blue light (385-550 nm) covering the cyan gap. The emission intensity reaches its maximum at approximately 450 nm and the emission peak is slightly shifted with varying Ce 3+ concentration, which is because Ce 3+ doping changes the crystal field around the luminescence center. The prepared phosphors showed promising properties for application in high-color rendering lighting. The crystal structure analysis via X-ray diffraction and Rietveld refinement and Gaussian fitting of the PL spectra indicated that Ce 3+ occupies the Sr 2+ and K + positions in the monoclinic host lattice. The optimal Ce 3+ content is 3at% and concentration quenching is attributed to the non-radiative energy transfer between the nearest-neighboring Ce 3+ ions. The temperature-dependent luminescence showed that the T 50 is 394 K for the KSrScSi 2 O 7 : x Ce 3+ materials. The thermal quenching is attributed to increased lattice vibrations and enhanced non-radiative transitions at elevated temperatures. The performance of the pc-WLED device fabricated with KSrScSi 2 O 7 : 3at%Ce 3+ was studied, and the device showed a high-color rendering index (Ra=93.8) and exceptional stability during operation.
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
危险品化学品经营许可证（带存储）