Optical Materials Express
·
2022
·Vol. 12
·期 8
·2942-2953
·
IF 3.074
Kai Sun,Xiaomeng Yin,Zhenqing Li,Hui Lin,Ruijin Hong,Dawei Zhang,Zhijun Zhang,Guanhaojie Zheng,Guanhaojie Zheng,Yuchong Ding
MgAl2O4:Cr3+ far-red emitting ceramic phosphors were prepared by the solid-state reaction method. The photoluminescence characteristics, especially the luminescence thermal stability, thermal conductivity, and its application in phosphor-converted LEDs were studied. Under 450 nm excitation, the ceramic phosphors exhibited an emission range of 650-750 nm and showed a narrow-band emission peaked at 688 nm. It also shows 708 nm and 718 nm far-red emission, which matches well with the absorption peak of the plant phytochrome PFR. The luminescence thermal stability of MgAl1.99O4:0.01Cr3+ was excellent. The integral intensity of the two emissions peaked at 708 nm and 718 nm at 500 K can maintain 98.27% and 98.24% of the counterparts measured at room temperature, respectively, showing zero thermal quenching behavior up to 500 K. The thermal conductivity of the MgAl1.99O4:0.01Cr3+ ceramic was 10.3 W·m-1·K-1. These results indicate that MgAl2O4:Cr3+ ceramic phosphors can be applied in plant lighting when packaged onto 450 nm blue LED chips.
研究领域:
材料科学
·
光学工程
·
植物学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Yibo Zhang,Shen Wang,Biao Liu,Yan Hao
MgAl 2 O 4 :Cr 3+ transparent ceramics were prepared by a hot-pressed sintering process with Y 2 O 3 and La 2 O 3 as sintering aids, and the effects on the microstructure, densification, optical transmission, and photoluminescent properties were investigated. The sintering aids of Y 2 O 3 and La 2 O 3 enhanced the relative density, reaching 99.33% with 2.4 wt% Y 2 O 3 and 99.24% with 0.8 wt% La 2 O 3 . La 2 O 3 also inhibited abnormal grain growth and obtained ceramics with uniform grain size. In addition, the optical transmission was also improved with Y 2 O 3 and La 2 O 3 as sintering aids. The transmission of the ceramic with 2.4 wt% Y 2 O 3 exceeded 78% in the region of 700–6000 nm and reached 83% at 1450 nm. Moreover, Y 2 O 3 and La 2 O 3 both contributed to improving the quantum yield of the ceramics, especially for Y 2 O 3 , and the quantum yield was about 0.354, which was approximately two times higher than that without R 2 O 3 . In summary, La 2 O 3 was helpful for improving sintering process, inhibiting grain growth, and homogenizing the grain size, while Y 2 O 3 was significant for enhancing the optical and photoluminescent properties.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
光电子学
·
固态发光材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·7069-7077
·
IF 3.9
Xiaomeng Yin,Ming Qiang,Hui Lin,Dawei Zhang,Ruijin Hong,Zhaoxia Han
In this work, we fabricated a novel spinel-type phosphor material MgAl 2− x Ga x O 4 doped with Cr 3+ by the high-temperature solid-state sintering method. The crystal field environment of the spinel was tuned by replacing the Al ions with Ga 3+ ions of different concentrations. The cell volume and D q / B gradient increase from 2.82 to 2.62 with increasing Ga 3+ ion doping concentration. This also implies a gradual decrease in the field strength of the crystal. Based on this, the excitation spectra of MgAl 1.995− x Ga x O 4 :0.5%Cr 3+ phosphors yield a redshift. Increasing the Ga 3+ ion doping concentration also improves the emission intensity and thermal stability of the phosphors, and the emission intensity of the Ga 3+ -doped phosphors is significantly increased. For a Ga/Al ratio of 1, the thermal stability of the phosphor emission is optimal. The emission intensity at 140°C can maintain 76% of the emission intensity at room temperature, indicating that appropriate Ga 3+ ion doping can improve the emission efficiency and thermal stability of the phosphors.
研究领域:
材料科学
·
光学
·
荧光粉技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 4
·5770-5775
·
IF 5.532
Yan Hao,Yibo Zhang,Biao Liu,Kuibao Zhang
In this work, MgAl 2 O 4 : Cr 3+ transparent ceramics have been synthesized by the hot press sintering techniques, and the effect of the sintering aid Gd 2 O 3 and its content on the densification, microstructure, and optical, photoluminescence was studied and discussed. The relative density reached 99.29% with 0.8 wt% Gd 2 O 3 as a sintering aid, and the optical transmittance at 686 nm and 1446 nm were approximately 76%. As Gd 2 O 3 content continued to increase, the grain size of the ceramics became smaller and uniform, accompanied by some pores with the size of ～1 μm. The ceramics with 4.0 wt% Gd 2 O 3 showed a higher transmittance, of 82% at 1446 nm. Additionally, Gd 2 O 3 was helpful for Cr 3+ in the sites of octahedral symmetry, which increased the quantum yield. The quantum yield of MgAl 2 O 4 : Cr 3+ with 0.8 wt% Gd 2 O 3 was about 0.175, which was 36% higher than that of ceramic without Gd 2 O 3 . In short, the sintering aid Gd 2 O 3 not only contributed to improving the densification, homogenizing the grain size, and heightening the optical transmittance but also enhanced the quantum yield of Cr 3+ .
研究领域:
材料科学
·
陶瓷
·
光学材料
·
固体物理
✓ 已验证
DOI
高影响因子
InfoMat
·
2025
·
IF 22.3
Gaochao Liu,Zhan Xiong,Weibin Chen,Shuai Zhang,Yuzhen Wang,Zhiguo Xia
High-power broadband near-infrared (NIR) light sources have attracted extensive interest toward emerging non-invasive imaging and detection applications. However, exploring highly stable luminescent materials with targeted broadband NIR emission remains a great challenge. Here, MgAl 2 O 4 :Cr 3+ translucent ceramics have been designed and fabricated by a spark plasma sintering method, and a giant redshift of the emission band occurs from 686 to 928 nm due to the decreasing local structural symmetry around the isolated Cr 3+ ions induced by the abundant cation vacancies. As Cr 3+ content increases, MgAl 2 O 4 :6%Cr 3+ ceramic realizes the optimized external quantum efficiency of 73% with broadband NIR emission centered at 890 nm and a full-width at half-maximum of 315 nm under 450 nm excitation. The next-generation laser-driven light source containing NIR ceramic provides an output power exceeding 2 W and a light conversion efficiency of 22% when pumped with a blue laser of 10 W·mm −2 . The proof-of-concept demonstrations in imaging and detection reveal the advantages of high-power and high-efficiency laser-driven broadband NIR light sources and promote future development in the chemical design of NIR emitters.
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）