JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Ye Zhang,Xue Lou,Xiaochun Chi,Quan Wang,Ning Sui,Zhihui Kang,Qiang Zhou,Hanzhuang Zhang,Li Li,Yinghui Wang
The temperature-dependent time-resolved spectroscopies are employed to investigate the hot carrier characteristics in MAPbBr 3 nanocrystals (NCs). Simultaneously, the absorption and photoluminescence data exhibits that MAPbBr 3 NCs pass through cubic phase and tetragonal phase in turn as the temperature drops. As the phase transition from the cubic phase to the tetragonal phase, the band gap narrows, the shallow defects population that participates in the carrier dynamics and the Longitudinal-optical phonon energy ( E LO ) decreases. We uncovered that the hot carrier can be induced in the MAPbBr 3 NCs through changing the photon flux and the temperature. Moreover, the hot carrier cooling time and the carrier heating effect in tetragonal phase improved in comparison with those in cubic phase, owing to the influence of bandgap, shallow defect and E LO as mentioned above. These results can help us to further understand the hot carrier characteristics in the perovskite MAPbBr 3 NCs for designing and optimizing the perovskite-based optoelectronic devices of high performance.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Z.M. Yu,L.F. Shen,D.S. Li,E.Y.B. Pun,J. Guo,H. Lin
Tb(acac) 3 (TAH) and Eu(TTA) 3 Phen (ETP) doped polyacrylonitriles (PAN) have been electrospun into heterogeneous hybrid TAH/ETP/PAN and core-shell structured [(TAH/PAN) core + (ETP/PAN) shell ] wire-shaped flexible nanofibers with diameter of ∼350 nm. Differential photon releasing behaviors reveal the double-color-emitting potential of Tb 3+ /Eu 3+ combination systems and verify the effectiveness of coaxial configuration in avoiding the cross-relaxation between different rare earth ions. Luminous fluxes of the hybrid and the coaxial systems exceed 283.5 and 326.3 μlm under the excitation of 308 nm UVB-LED pump source, respectively. By adopting coaxial electrospun configuration, the color coordinates are tuned from (0.561, 0.332) in TAH/ETP/PAN to (0.435, 0.366) in [(TAH/PAN) core + (ETP/PAN) shell ] fibers, which demonstrates that the core-shell structure is promising to extend the dimension of color tuning. Nanofibrosis and electrospun configurations furnish a desired approach to develop multifunctional one-dimensional nanomaterials for color displays and optoelectronic sensors .
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 10
·4214
·
IF 4.6
Tianyun Du,Xiaojie Xue,Xiuxun Han
Rare earth silicate phosphors of high quantum efficiency with a stable performance are promising materials in the fields of display and illumination. The grain sizes of products synthesized via the conventional solid-state reaction method are usually too large to satisfy the requirements of color cast and extraction efficiency in high-resolution light-emitting devices (LEDs). We designed a synthetic route and successfully fabricated rare earth silicate NaGd9Si6O26(NGSO) sub-microcrystals with a size ranging from 550 to 1200 nm. The reaction mechanism and optical properties were systematically investigated. The quantum efficiency of Eu3+-activated NGSO sub-microcrystals was about 36.6%. The LED encapsulated with these sub-microcrystals showed lower color deviation and higher lumen efficiency and lumen flux compared to that with NGSO fabricated using the conventional solid state reaction method.
研究领域:
材料科学
·
光电技术
·
化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 11
·期 2
·488-496
·
IF 8.067
Min-Hang Huang,Qiang-Qiang Zhu,Shuxing Li,Yue Zhai,Hong Zhang,Le Wang,Rong-Jun Xie
The key to developing laser-driven solid-state lighting lies in high-performance color converters, which must be thermally robust under the high-power density excitation of a laser. Phosphor-in-glass (PiG) films are considered as a kind of promising color converter for laser lighting, but the poor thermal dissipation of the glass matrix will cause large thermal quenching of the PiG films and hence low luminous flux of lighting sources. In this work, Al2O3 particles, acting as a heat transfer medium, are introduced into the La3Si6N11:Ce3+ (LSN:Ce3+) PiG film to form a composite color converter for realizing high-brightness laser lighting. By optimizing the ratio of glass frits to Al2O3 as well as the film thickness, the Al2O3–LSN:Ce3+ composite PiG film shows a luminance saturation threshold of 23.08 W mm−2, which is 26.3% higher than that of the Al2O3-free LSN:Ce3+ PiG film (18.27 W mm−2). The luminous flux of the composite PiG film under blue laser excitation is improved by 51.4% and reaches 3120 lm, and the luminous flux of the laser-driven white light can reach up to 2886 lm. It indicates that the Al2O3–LSN:Ce3+ composite PiG film would be an interesting color converter for producing high-brightness laser-driven white light.
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
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 7
·1818-1824
·
IF 2.162
Yufeng Huang,Yakai Feng,Xujun Sun,Ying Han,Dongshun Liu,Xiaohua Tan
Organic silicones have been used as encapsulant materials for light-emitting diodes (LEDs) for many years, while their performances need to be improved in order to satisfy the requirements of high-power LEDs. A ZrO 2 /silicone hybrid resin (ZHR) was synthesized for LEDs encapsulation by in situ sol-gel reactions. The oligosiloxane was synthesized as polymeric matrix by nonaqueous sol-gel condensation using diphenylsilanediol (DPSD), vinyltrimethoxysilane (VTMS), and 3-methacryloxy propyl trimethoxysilane (MPTMS) as monomers. Then zirconium propoxide was added into this polymeric matrix to be hydrolyzed to obtain the hybrid resin with a uniform dispersion of ZrO 2 nanoparticles. The Si–O–Zr covalent bond was detected and benefited for excellent dispersibility of the ZrO 2 nanoparticles and the well compatibility between organic and inorganic phases. The cured ZHR with 5 wt% ZrO 2 content showed high light transmittance (greater than 80% in visible light range), high refractive index (=1.56), and high thermal stability (no yellowing at 150°C for 240 hours). The luminous flux of the LED chip with ZHR encapsulant was 10% higher than that of the pure silicone resin, suggesting that ZHR has great application potential in the field of LED packaging.
研究领域:
材料科学
·
化学工程
·
光电
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Gaohong Wu,Xiangjia Sun,Yanrong Liang,Jiaying Zheng,Yulan Xie,Zhaoping Chen,Jian Xu,Weidong Xiang,Xiaojuan Liang
To address the thermal management challenge in phosphor-in-glass (PiG) materials for laser lighting due to low glass matrix thermal conductivity, this study developed YAG:Ce 3+ -Al 2 O 3 PiG composites reinforced with Al 2 O 3 particles, achieving a thermal conductivity of 78.6 W/(m·K). A TiO 2 reflective layer optimized for reflection and light conversion was introduced between the AlN substrate and PiG layer. Systematic optimization of Al 2 O 3 content and preparation conditions yielded YAG:Ce 3+ -Al 2 O 3 PiG composites with exceptional performance: maximum luminous flux (LF) of 2515 lm under blue laser excitation, saturation threshold (ST) of 27.57 W/mm 2 , and luminous efficiency (LE) of 174.7 lm/W. LF and ST increased by 184.5 % and 167.4 %, respectively, compared to non-Al 2 O 3 counterparts. The surface temperature of 9 wt% Al 2 O 3 PiG reached 363.85 K, 34.4 % lower than the working temperature of the sample without Al 2 O 3 addition. Stable light emission and high photothermal stability confirm its potential as a high-brightness laser lighting material.
研究领域:
材料科学
·
光学工程
·
热管理
·
固态照明
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 6
·862-873
·
IF 11.534
Huang Qiugui,Lin Hang,Wang Bo,Lin Shisheng,Wang Pengfei,Sui Ping,Xu Ju,Cheng Yao,Wang Yuansheng
Up-to-date laser-driven lightings confront a challenge of simultaneously achieving good photometric and chromatic performances. Herein, the coupling of “patterned package design” and “phosphor wheel” was proposed and demonstrated effectively to deal with this tough issue, based on a new architecture of CaAlSiN 3 :Eu 2+ (CASN:Eu) glass ceramic film (GCF) on Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce) GC plate. The fabricated composite has no interface between the two functional layers and retains the admirable luminescent features from CASN:Eu and YAG:Ce for the microstructural integrity during co-sintering. The studies on laser-microcrystalline interactions reveal that the luminescence saturation is almost determined by thermal quenching for YAG:Ce, but is ascribed to thermal/intensity quenching which are equally crucial for CASN:Eu. Benefiting from the elaborate architecture design, good color chromaticity tunability was obtained, and severe photon reabsorption was reduced. Moreover, accompanied with the rotation induced increase of thermal convection to air and pulse-like excitation, the constructed lighting engine under blue laser driven shows bright white light with luminous flux (LF) higher than 1000 lm, adjustable chromaticity from cool to warm, and improved color rendering index (CRI) approaching to 70.
研究领域:
光学
·
材料科学
·
照明工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jian Xu,Xin Liu,Zikang Yu,Hongjin Zhang,Zixiang Zhang,Yun Mou,Mingxiang Chen,Yang Peng,Qing Wang
Laser-driven white lighting is believed to be a future-oriented high-brightness solid-state light (SSL) source, which is confronted with a severe challenge in developing a laser-driven color converter with efficient thermal management. Herein, a unique architecture of phosphor-in-glass film bonded with a microchannel cooling (PiGF-MC) converter was proposed to enable high luminescence saturation for high-brightness laser-driven white lighting. The PiGF consisted of yellow-emitting Y 3 Al 5 O 12 :Ce 3+ (YAG) was sintered on an alumina substrate and then soldered on a liquid-cooled microchannel radiator, which realizes outstanding heat dissipation performance of laser-driven PiGF. The PiGF-MC converter possesses luminance saturation threshold under a high laser power density of 21 W mm −2 , 2.3 times that of the traditional PiGF-alumina converter (∼9 W mm −2 ). High-brightness laser-driven white light is achieved by the PiGF-MC with a high luminous flux of 2953 lm@21 W mm −2 , and long-term stable optical performance is simultaneously realized. The working temperatures of laser-driven PiGF-MC are all lower than 200 °C under various laser powers. This finding demonstrates the broad prospect of the proposed PiGF-MC converter architecture for next-generation high-brightness laser-driven white lighting.
研究领域:
光学
·
材料科学
·
热能工程
·
照明技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yuqin Guo,Guojuan Wang,Linrong Qiu,Chengwu Hong,Shuxing Li,Rong-Jun Xie
Using blue lasers to excite green-emitting phosphors offers a compelling solution to address the “green gap” issue, providing a high-brightness green light source for underwater wireless optical communication (UWOC). However, current green-emitting phosphors show poor light conversion efficiencies or inadequate luminance saturation thresholds, impeding the development of brighter green light sources. Herein, the porous Lu 3 Al 5 O 12 :Ce phosphor ceramics are designed, which shows no change in quantum efficiency (82%) even after 6000 h of extended aging. This design results in a substantial improvement in light conversion efficiency (61.6%), luminous efficacy (286 lm·W⁻¹), and an exceptional luminance saturation threshold of 33 W·mm⁻ 2 , culminating in a maximum green light flux of 4720 lm. Moreover, the high-directionality green light source device has been fabricated that achieves an illuminance of 6081 lx at a distance of 10 meters (15.0 W blue laser irradiation) with the electro-optical conversion efficiency up to 26.3%, much higher than that using green laser directly (usually <20%). This setup enables long-range underwater transmission of 65.3 meters with a peak data rate of 3.45 MHz, opening up new avenues for innovative advancements in UWOC technology.
研究领域:
光学通信
·
光子学
·
材料科学
·
固态照明
·
水下技术
·
激光技术
·
通信工程
✓ 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）