Nano-Micro Letters
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2023
·Vol. 16
·期 1
·1-13
·
IF 26.6
Xiao Guang,Li Hao,Yu Zhizhou,Niu Haoting,Yao Yagang
Highly thermally conductive composite films with elimination of graphene nanosheet wrinkles prepared by a constrained drying strategy of in-plane stretching.
Reveals the mechanism of graphene nanosheet wrinkle elimination to improve the thermal conductivity of composite films and demonstrates its use as a heat sink film for cooling flexible LED chips and smartphones.
研究领域:
材料科学
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热管理技术
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纳米科技
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xin Xie,Wanyin Ge,Ye Tian,Qian Zhang,Maohao Yang,Chenge Wu,Peng He,Honglei Yin
To develop continuous broadband emission near-infrared (NIR) phosphors compatible with blue LED chips, numerous Cr 3+ -Yb 3+ co-doped phosphors have been synthesized. However, the emission spectra of Cr 3+ vary significantly across different matrix materials, while Yb 3+ maintains a relatively stable emission spectrum. This variation leads to notable luminescence depressions between 850 and 900 nm in many Cr 3+ -Yb 3+ co-doped phosphors. To address this emission spectrum gap, we utilized Cr 3+ as a sensitizer and introduced Nd 3+ as the luminescence center within the La 3 Sc 2 Ga 3 O 12 matrix material, establishing a Cr 3+ -Nd 3+ energy transfer channel. Under 480 nm excitation, we tuned emission peaks at 800 nm (Cr 3+ ) and 881 nm (Nd 3+ ). The stable NIR emission of Nd 3+ effectively compensates for the missing spectrum in Cr 3+ -Yb 3+ co-doping. The Cr 3+ -Nd 3+ energy transfer process was thoroughly analyzed using diffuse reflection spectrum, excitation spectrum, and fluorescence decay curves. The LSGO:0.125Cr 3+ , 0.03Nd 3+ compound with the best optical performance was packaged with a 480 nm LED chip to create a NIR light source. At a working current of 10 mA, it achieved a photoelectric conversion efficiency of 9.45 %, demonstrating its potential for applications in non-destructive detection and luminescence thermometry. This work presents a novel strategy for tuning NIR spectral distribution and developing continuous broadband NIR phosphors.
研究领域:
材料科学
·
光学
·
光子学
·
光谱学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Zhiyu Qin,Langping Dong,Ganghua Zhang,Yufeng Liu,Guoying Zhao,Yongzheng Fang,Jingshan Hou
In this paper, a novel violet excited reddish-orange emitting Sr 3 Ga 2 Sn 1 · 5 Si 2 · 5 O 14 :Sm 3+ (SGSSO:Sm 3+ ) phosphor with high thermal stability was designed and synthesized by the high temperature solid state reaction method for the first time. The photoluminescence (PL) properties of the SGSSO:Sm 3+ phosphors were investigated systematically. Under 402 nm violet light excitation , SGSSO:Sm 3+ phosphor shows reddish-orange emission at 598 nm that is attributed to the 4 G 5/2 → 6 H 7/2 transition of the Sm 3+ ions. Importantly, the PL intensity of SGSSO:Sm 3+ at 423 K can maintain 87% of the initial value at room temperature . The high thermal stability of Sm 3+ in SGSSO was speculated to be attributed to the energy transfer mechanism of trap formed by the hetero-valent substitution of Sm 3+ at Sr 2+ sites. Finally, a WLED has been fabricated by combing the violet LED chip with the as-prepared reddish-orange emitting phosphor , commercial blue BaMgAl 10 O 17 :Eu 2+ (BAM:Eu 2+ ) and green (Ba,Sr) 2 SiO 4 :Eu 2+ ((Ba,Sr)S:Eu 2+ ) phosphors. The results indicated that the as-prepared SGSSO:Sm 3+ phosphor can be a potential candidate of the reddish-orange component for violet chip pumped white-light-emitting-diodes.
研究领域:
材料科学
·
光电子学
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固态照明
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无机化学
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应用物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Kaiyuan Deng,Yahong Jin,Lifang Yuan,Haoyi Wu,Yihua Hu
Phosphor-converted light-emitting diode (pc-LED) technology, as artificial lighting source, is the most promising option for providing power for plant growth in future smart agricultural factories. However, developing red phosphors with the desired emission spectral range and good thermal stability is still experimental. In this study, an Mn 4+ -doped BaZrGe 3 O 9 red-emitting phosphor with remarkable thermal stability is reported. The red emission, spanning the wavelength range of 600–800 nm, matches the absorption range of chlorophyll a, b and phytochrome (P r ). Its good thermal stability at 150 °C is in addition to its emission intensity, which is 81.7 % of its room-temperature intensity. Co-doping with Ca 2+ contributes to a 1.7-fold increase in the red emission intensity at room temperature. The encapsulation of the present phosphor onto UV LED chips produces red emitting LED devices, which can be used for garlic and corn cultivation. The implementation reveals that the six-hour artificial red light illumination supplement is the most effective and significant means to promote garlic and corn growth. The as-obtained red-emitting phosphor may be a promising candidate for pc-LEDs promotion of crop growth in agricultural factories.
研究领域:
农业工程
·
植物生理学
·
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Jinning Wang,Qiufeng Shi,Konstantin V. Ivanovskikh,Lei Wang,Jianwei Qiao,Haijie Guo,Ping Huang
A series of Mn 4+ -doped NaSr 10 Y 5 W 4 O 30 (NSYWO) phosphors have been successfully synthesized and further characterized to estimate their potentials for application as a far-red emitting component of pc-LED. An XRD analysis and crystal structure refinement have been carried out to characterize its quality. The doping concentration and temperature (80–500 K) dependent luminescence properties as well as decay kinetics have been studied and analyzed. It has been found that Mn 4+ substitutes for W 6+ sites resulting in far-red emission at 688 nm. The temperature quenching is attributed to thermal activation of an electron from Mn 4+ 2 E g to 4 A 2g state via crossover, yielding an activation energy of 0.35 eV. Furthermore, to assess practical application of the novel phosphor, a blue-emitting LED chip combined with NSYWO: 0.8 mol% Mn 4+ has been packaged. The light from both the blue-emitting LED chip and NSYWO: Mn 4+ phosphor was shown to be effectively utilized, revealing a good promise for application of the phosphor in the field of plant growth lighting.
研究领域:
材料科学
·
光电
·
植物生物学
·
光子学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Chunhao Wang,Shuai Zhang,Qiongyu Bai,Yuan Wang
From the practical point of view, the luminescent thermal behavior of phosphors is an important factor. In this work, two factors are found to influence the thermal quenching behavior of Eu 3+ in a series of Eu 3+ doped K 5 Bi(Mo x W 1- x O 4 ) 4 solid solution phosphors. These factors are the energy of the charge transfer state (CTS) and the thermal ionization process. With the introduction of Mo in the host matrix, the energy of CTS decreases, and the thermal ionization process is enhanced, which leads to a deterioration of thermal stability in solid solution phosphors. The thermal stability is improved by increasing the doping content of Eu 3+ , which may correlate to the weakening of the thermal ionization process. The K 5 Bi 0.7 (Mo 0.5 W 0.5 O 4 ) 4 :0.3Eu phosphor possesses favorable color stability and color purity at high temperatures. Meanwhile, such phosphor matches well with a 365 nm LED chip and exhibits intense and pure red emission at a drive current of 200 mA.
研究领域:
材料科学
·
光电技术
·
磷光技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Heng Xie,Yu Du,Xiaolong Li,Congyuan Zhang,Weilong Zhou,Xiao Yang,Zhiyong Chang,Ting Wu,Jinping Qu
The development of new materials for resource and energy recycling has emerged as a primary focus in addressing global energy and environmental sustainability challenges. Inspired by traditional Chinese architecture, a smart roof tile (SRT) is scientifically designed, which incorporates hierarchical micro-nanostructured polyethylene/silica/barium sulfate composites (IH-PSB), semiconductor power generation modules, and LED chips. Leveraging the combined effects of surface and interface functionalities , the IH-PSB demonstrates exceptional sub-ambient cooling capabilities, resulting in its surface and bottom temperature being 5.4 °C and 12.1 °C lower than the ambient temperature, respectively. Additionally, the precisely controlled heterogeneous wettability , with a contact angle of approximately 151° and a roll-off angle of around 32°, allows the IH-PSB to efficiently condense moisture and transport droplets. Benefiting from the excellent radiation cooling performance and precisely controlled heterogeneous wettability , the IH-PSB exhibits remarkable passive sub-dewpoint cooling efficiency coupled with efficient water harvesting performance. During a one-month outdoor experiment, the IH-PSB operated stably and continuously without any electrical input, maintaining a mass flux ranging from ∼23.2–50.0 g m −2 h −1 . Interestingly, the SRT system efficiently harnesses waste heat generated by the LEDs while simultaneously regulating their temperature effectively. The development and utilization of the SRT offer a sustainable, energy-efficient, and forward-thinking solution that addresses global water scarcity and energy crises.
研究领域:
材料科学
·
环境工程
·
能源工程
·
水资源管理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）