NANOTECHNOLOGY
·
2022
·Vol. 33
·期 26
·265002
·
IF 3.953
Xiaohui Fan,Yang Wang,Bo Li,Chang Shen,Zhengguang Sun,Yuan Zhan,Yuhong Zhang
Carbon quantum dots (CDs) have attracted tremendous interest owing to their idiosyncratic functions and wide-ranging applications. However, it remains a great challenge to empolder an integrated CDs combining high luminescence, biocompatibility and luminescence color tunability for bioimaging via simple approach. In this work, pH-responsive carbon quantum dots (Si-CDs) with high luminescence (quantum yield = 74.8%) were fabricated by one-step hydrothermal method using (3-mercaptopropyl) triethoxysilane (KH-580) as modifier for the first time. The optical properties of the as-prepared Si-CDs can be controlled from obvious green–blue–violet transformation by altering the pH. More importantly, the change is reversible and repeatable. In addition, the Si-CDs have good biocompatibility and chemically inert in vitro cell system simulation. Such non-toxic, environmental friendly, low-cost, inert CDs materials are promising candidates for biomedical and pH-sensitive sensors.
研究领域:
生物医学
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材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 6
·1901485
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IF 8.286
Wenzhen Lv,Ling Li,Mingguang Li,Ligang Xu,Wei Huang,Runfeng Chen
Completely inorganic lead halide perovskite (CsPbX 3 , X = Cl, Br, I) nanocrystals (NCs) are attracting increasing attention due to their outstanding luminescent properties, but their inherently poor stability is a severe impediment to further practical applications. Here, a facile two-step synthetic procedure for preparing highly stable CsPbX 3 NCs with the assistance of kaolinite lamellae (KL) is demonstrated. Systematic investigation shows that the cesium ions can be anchored tightly to the KL with the aid of strong Coulombic force interactions. These trigger the efficient growth of orthorhombic phase CsPbX 3 NCs on the KL surfaces in a highly ordered manner. As a benefit of the inhibited aggregation caused by isolation and the anchoring effect of KL, the CsPbBr 3 -KL composites display high luminescent efficiency (up to 73.0%) and excellent stability in air (>240 h). An efficient, stable, white light-emitting diode device is fabricated by packaging green CsPbBr 3 -KL and red CsPb(Br 0.5 I 0.5 ) 3 -KL composites on a blue GaN chip. These findings demonstrate the first attempt to improve the stability of CsPbX 3 NCs by designing composites with materials having natural layers. This should shed important light on the preparation of high-efficiency, stable, and color-tunable perovskite materials for applications requiring high-performance devices.
研究领域:
材料科学
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光电化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2021
·Vol. 13
·期 6
·3860-3867
·
IF 7.79
Meng Li,Xiao Zhang,Ping Yang
Silica coating can effectively solve the stability issue of lead halide perovskite nanomaterials. However, it is difficult to achieve aqueous SiO2 coating on hydrophobic CsPbBr3 nanocrystals (NCs). In this paper, the hydrolysis process of tetramethoxysilane was controlled to get a homogeneous SiO2 coating or a NC/SiO2 Janus structure. In step 1, the Cs4PbBr6 NCs were silanized using partially hydrolyzed tetramethoxysilane (PH-TMOS). During this process, the Si–OH groups which came from PH-TMOS were absorbed onto the surface of the Cs4PbBr6 NCs with the removal of hydrophobic oleic acid (OA) ligands. In step 2, phase transformation from Cs4PbBr6 to CsPbBr3 occurred owing to the injection of water. Meanwhile, further hydrolysis of TMOS took place and generated cross-linked Si–O–Si. Because the silanization in step 1 created lots of growth sites, the condensation of SiO2 was not limited to the interface between water and hexane. After growing for 12 h, the fully covered CsPbBr3@SiO2 capsules were prepared. The anion exchange reactions of the CsPbBr3@SiO2 capsules were studied. Only one even and symmetric PL peak was apparent during the anion exchange process, which was different from the bare CsPbBr3 NCs. This result demonstrated that the SiO2 shell can act as a buffer layer to block the direct contact of CsPbBr3 with the excess PbBr2 precursor in solution. Compared with the CsPbBr3 NCs, CsPbBr3@SiO2 showed better stability in polar solvent and air. A bright green emission was also observed under UV light after 90 days. The successful preparation of CsPbBr3@SiO2 capsules with enhanced stability paves the way for the further development of lead halide perovskite nanomaterials.
研究领域:
材料科学
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纳米技术
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 35
·10783-10788
·
IF 6.641
Wenqiang Liu,Guodong Yuan,Yang Zhang,Qi Wang,Shuai Zhao,Zhiqiang Liu,Tongbo Wei,Junxi Wang,Jinmin Li
All-inorganic perovskite nanocrystals (NCs) have recently emerged as a new class of materials due to their tunable bandgaps and high photoluminescence quantum yields (PLQYs). The origin of the enhancement of PLQY of CsPbBr3 NCs is usually attributed to the efficient passivation of the surface halide vacancies creating nonradiative recombination sites. In this work, Br-rich CsPbBr3 NCs with a PLQY of 97% were prepared using an extreme excess of Br source with Br/Pb of 4.5/1 from the ligand itself at room temperature. Br-rich CsPbBr3 NC based light-emitting devices were fabricated under ambient conditions, exhibiting the maximum current efficiency of 1 cd A−1 at the luminance of 750 cd m−2. First principles calculations indicate that Br interstitials can form the strong localized states. Such localized effect can prevent photogenerated carriers from defusing to non-radiative recombination centers, thus being responsible for the high emission efficiency.
研究领域:
材料科学
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纳米技术
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光电
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Tao Huang,Hui Peng,Qilin Wei,Chengyu Peng,Ye Tian,Shangfei Yao,Xinxin Han,Bingsuo Zou
If we introduce transition metal ions with spins into an organic-inorganic halide perovskite compounds, interesting spin dependent optical properties may be seen in this system. This paper reports an organic-inorganic hybrid manganese ion doped lead halide crystal incorporated by TDMP (trans-2,5-dimethylpiperazinium), it gives not only the STE1 (polaronic exciton), usually brought up by the enhanced electron-phonon coupling in the amine incorporated compound, but also give a novel bipolaronic exciton (STE2) for the paired charge state formation due to the incorporation of bi-amine cationic molecules, a excitation by the polaronic molecule due to enhanced electron-phonon coupling and neighboring correlation out of the Mn ion ferromagnetic spin coupling in the lattice at slightly high doping. Such magnetic bipolaron state could often be accompanied by several multiphonon Raman modes and ferromagnetism. It is even interesting that this state can give super-high red emission with PLQY at ~92.5% at room temperature. Moreover, the emission color and intensity could also be modulated by the Mn doping concentration, temperature, and laser excitation power. The low doping products can give green emission out of single Mn d-d transition at very low temperature or high laser excitation power. The intermediately doped products can give white emission out of STE1 and STE2. The highly doping products give red emission out of STE2 (bipolaron states) at room temperature or low laser power. These interesting phenomena reflected the microscopic interactions between spins, carriers and phonons in the products, which can be found applications in the future fields of photonics and spintronics.
研究领域:
材料科学
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光电
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自旋电子学
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光子学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Rui Cao,Xinning Zhou,Haitao Dai,Yong Wang,Yin Xiao
CPL-active flexible materials with high luminescence dissymmetry factor ( g lum ) and luminescent quantum yield are indispensable for 3D displays, wearable devices and so on. Perovskite has drawn much attention due to its fascinating photoelectric properties as well as its abundant applications. However, the existing strategies are inefficient in acquiring perovskite NCs with high g lum . In this work, thermoregulated CPL-active flexible polymer/perovskite hybrid materials with high g lum by the creation of chiral photonic bandgap in polymer film with cholesteric domains using toluene as the dielectric media is reported. Based on selective CPL reflection, a satisfied CPL with a maximum g lum of 0.6 is achieved. Importantly, the chiral photonic bandgap center of the polymer film can be easily tuned by thermal annealing at different temperatures to adapt various perovskite NCs with full-spectral emission. The handedness of CPL of hybrid materials can be regulated with and without dielectric media. The presence of the flexible polymer makes hybrid materials a candidate to achieve patterned display applications. Additionally, the polymer/perovskite hybrid materials show excellent stability thanks to the encapsulation effect from polymers. This work provides a facile and general approach to induce adjustable CPL in the whole visible spectrum with high g lum and photoluminescence quantum yield (PLQY).
研究领域:
材料科学
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光电技术
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光子学
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纳米技术
✓ 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
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材料科学
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热能工程
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照明技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Horizons
·
2023
·Vol. 11
·期 5
·1294-1304
·
IF 13.3
Xu Li,Bibo Lou,Xu Chen,Meng Wang,Huifang Jiang,Shuailing Lin,Zhuangzhuang Ma,Mochen Jia,Yanbing Han,Yongtao Tian,Di Wu,Wen Xu,Xinjian Li,Chonggeng Ma,Zhifeng Shi
Lead halide perovskite nanocrystals (NCs) are highly promising for backlighting display applications due to their high photoluminescence quantum yields (PLQYs) and wide color gamut values. However, the practical applications of blue emitters are limited due to the toxicity of lead, unstable structure, and unsatisfactory PLQY. Herein, we report the successful synthesis of divalent europium-based perovskite CsEuBr3 NCs using a modified hot injection method. By optimizing the reaction conditions, the CsEuBr3 NCs display a deep-blue emission at 443 nm with a full width at half maximum (FWHM) of 28.5 nm, a color purity of 99.61%, and a record high PLQY of 93.51% for deep-blue narrow-band emissive lead-free perovskite NCs as far as we know. The emission mechanism of CsEuBr3 NCs is proved through first-principles calculations and spectral analysis. Notably, the CsEuBr3 NCs exhibit remarkable stability when exposed to high temperature, UV irradiation, and long-term sealed storage. The incorporation of CsEuBr3 NCs into polydimethylsiloxane (PDMS) serving as a converter is utilized for white light-emitting devices (WLEDs). WLEDs for backlight displays achieves a wide color gamut of 127.1% of the National Television System Committee standard (NTSC), 94.9% coverage of the ITU-R Recommendation BT.2020 (Rec.2020), and their half-lifetime is up to 1677 h, providing a promising pathway for highly efficient, environment-friendly and practical liquid crystal display backlights.
研究领域:
材料科学
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光电技术
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显示技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）