Materials Today Chemistry
·
2022
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IF 7.613
S. Zhang,Y. Liu,J. Yin,X. Zhang,Y. Li,L. Su,Z. Zhou,M. Xia
Plant factory, a new agricultural planting technology, has emerged and rapidly grown in recent years, with phosphor conversion light emitting diodes (pc-LEDs) considered as the first choice of source light for the plant factory. In this study, a new type of Cr 3+ -activated Li 2 MgTi 3 O 8 phosphor (LMT: Cr 3+ ) was synthesized by high temperature solid state method. X-Ray diffraction patterns showed that there was no detectable impurity in these samples. The photoluminescence spectra revealed that this phosphor can emit far-red light with the peak at 740 nm excited by ultraviolet and blue light, overlapped well with the P FR . After introducing Zn 2+ ions (LMT: Cr 3+ , Zn 2+ ), the luminescence intensity increases by 46% mainly due to the increase of lattice distortion, and internal quantum yield was improved from 25.4% to 41.3% under 365 nm excitation. Finally, the pc-LED devices, consisting of 470 nm chip coated with the optimal phosphor, exhibited good luminescence and overlapping with P FR . These results indicate that the LMT: Cr 3+ , Zn 2+ phosphor has the potential application in modern agriculture.
研究领域:
材料科学
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光电技术
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农业技术
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植物生理学
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2024
·
IF 9.8
Hui Zhu,Yanan Li,Yuexiang Xi,Chunli Xin,Cheng Zhou,Zhe Yang,Lang Ruan,Yanyue Li,Yao Peng,Maxim S. Molokeev,Andrey Zolotov,Jing Wang,Zhi Zhou,Mao Xia
β-Al 2 O 3 phosphors show good optical properties for highly symmetric lattices and dense frameworks. Here, an abnormal lattice shrinkage phenomenon is found in BaMg 1-x Zn x Al 9.8 O 17 : Cr 3+ (BM 1-x Z x A: Cr 3+ ) phosphors, which can be attributed to the variation in the covalency of the chemical bond. Accordingly, the denser crystal structure caused by the abnormal shrinkage improves the luminescent intensity (67%↑) and the thermal stability (69%→76%@150 °C). Internal/external quantum efficiency (IQE/EQE) of BZA: 0.2Cr 3+ reaches 95% and 52.7%, respectively. In addition, the preferential occupation of the Cr 3+ ion is discussed through the crystal field strength calculation, low-temperature spectra, and fluorescent lifetime. The unique spectrum of the phosphor derives from the occupation of Cr 3+ on the octahedral sites (Al4 and Al1) and the formation of Cr 3+ -Cr 3+ coupling pairs. Finally, the high matching rate between the absorption curve of plant pigment P fr and the EL spectrum of the as-prepared pc-LED expresses that it can be applied in plant lighting.
研究领域:
材料科学
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光学
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固体化学
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植物生物学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xin Yang,Wei Lü,Jin Xiang Lim,Biao Wang
There is strong demand of exceptional efficiency for near-infrared (NIR) phosphors for next-generation integrated and intelligent multifunctional light-emitting diode (LED) devices. Designing NIR phosphors with excellent efficiency that simultaneously meet multiple application requirements is challenging. Hence, this work focuses on the NIR optical properties and the corresponding multifunctional applications for Cr 3+ activated LaMgAl 11 O 19 (LMAO) phosphors. The blue light excitable LMAO:Cr 3+ phosphors can produce intense NIR emission ranging from 630 to 1000 nm with an 95.8% internal quantum efficiency as well as excellent thermal stability (I 423 K /I 303 K = 75.9%). Additionally, benefiting from the strong correlation between fluorescence lifetime and ambient temperature, the LMAO:Cr 3+ phosphors were showed promising potential for application in temperature sensing. Notably, the NIR phosphor-converted LED devices based on LMAO:Cr 3+ phosphors and commercial blue LED chip were self-built, which exhibiting great potential for indoor plant cultivation, night vision, and nondestructive detection. This study describes the highly efficient LMAO:Cr 3+ phosphors preparation and the corresponding multifunctional applications in the fields of optical thermometry, indoor plant cultivation, night vision, and nondestructive detection, which is crucial for the next-generation integrated and intelligent multifunctional LED devices.
研究领域:
材料科学
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光学工程
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固态照明
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温度传感技术
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植物生长技术
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无损检测
✓ 已验证
产品关联
DOI
高影响因子
Science China-Materials
·
2025
·
IF 7.4
Peng Chunli,Tang Baoling,Zhang Xuejie,Molokeev Maxim S.,Zhang Haoran,Lei Bingfu
Near-infrared (NIR) spectroscopy has significantly advanced NIR light sources. However, creating NIR emitters with optimal luminescence properties, high thermal stability, and adjustable emission peaks poses a critical challenge for future smart NIR devices. We introduced a chemical unit cosubstitution strategy by incorporating Ca 2+ and Sn 4+ ions into the garnet structure. Through this approach, Y 3− y Ca y Ga 4.95− y Sn y G 12 :0.05Cr 3+ ( y = 0–1) phosphors were developed by modulating the A&C ligands, resulting in emission centers ranging from 708 to 768 nm. The modified local environment of Cr 3+ accounts for the increased light intensity (2.71 times) and broadening observed. Furthermore, this study investigated the impact of varying Cr 3+ concentrations (Y 2.6 Ca 0.4 Ga 4.6− x Sn 0.4 G 12 : x Cr 3+ ) on the production of high-performance phosphors. Compared with Y 3 Ga 4.93 G 12 :0.07Cr 3+ , the optimized phosphor exhibited exceptional external quantum efficiency (EQE = 34.96%). The luminescence enhancement is attributed to an increase in radiative transitions caused by octahedral Jahn-Teller distortion, whereas the notable thermal stability (91.3% at 423 K) is attributed to the presence of weak electron-phonon coupling (EPC) and oxygen vacancy (O V ) defects. Finally, by combining it with a 450 nm blue LED chip, we constructed a near-infrared phosphor-converted LED (NIR pc-LED) device with superior electroluminescence efficiency (18.8% @ 100 mA), increasing the ultralow quenching rate (< 5% intensity loss after 30 days of operation) and demonstrating remarkable performance in plant lighting applications.
研究领域:
材料科学
·
光学材料
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固态照明
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光子学
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植物生物技术
✓ 已验证
产品关联
DOI
高影响因子
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