CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Qingyun He,Enrou Mei,Xiaojuan Liang,Weidong Xiang
Here, polyvinyl butyral (PVB) films-protected CsPbBr 3 /Cs 4 PbBr 6 halide perovskite solids (HPSs) were successfully synthesized. The optical properties and structure of HPSs@PVB were studied, finding the photoluminescence quantum yields (PLQYs) of this novel composite material is as high as 60.4%. More importantly, HPSs@PVB has excellent thermal cyclability, water and ultraviolet (UV) resistance. In addition, HPSs@PVB was further applied to light emitting diodes (LEDs) and displays. By combining green-emitting HPSs@PVB and red-emitting CsPbBrI 2 NCs@PVB with InGaN 460 nm blue chip, white light emitting diode (WLED) device can be successfully fabricated. And the device exhibits good stability and the color gamut is as wide as 126%, reaching 94% of Rec. 2020. This work proposes a simple approach to solve the challenging stability issue of perovskite nanocrystals (NCs), having a positive implication for their practical application in LEDs and display backlights.
研究领域:
材料科学
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光学工程
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显示技术
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高影响因子
Light-Science & Applications
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2020
·Vol. 9
·期 1
·1-11
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IF 13.714
Liu Kai-Kai,Liu Qian,Yang Dong-Wen,Liang Ya-Chuan,Sui Lai-Zhi,Wei Jian-Yong,Xue Guo-Wei,Zhao Wen-Bo,Wu Xue-Ying,Dong Lin,Shan Chong-Xin
Poor stability has long been one of the key issues that hinder the practical applications of lead-based halide perovskites. In this paper, the photoluminescence (PL) quantum yield (QY) of bromide-based perovskites can be increased from 2.5% to 71.54% by introducing water, and the PL QY of a sample in aqueous solution decreases minimally over 1 year. The enhanced stability and PL QY can be attributed to the water-induced methylamino lead bromide perovskite (MAPbBr 3 )@PbBr(OH). We note that this strategy is universal to MAPbBr 3 , formamidine lead bromide perovskite (FAPbBr 3 ), inorganic lead bromide perovskite (CsPbBr 3 ), etc. Light-emitting devices (LEDs) are fabricated by using the as-prepared perovskite as phosphors on a 365 nm UV chip. The luminance intensity of the LED is 9549 cd/m 2 when the driven current is 200 mA, and blemishes on the surface of glass are clearly observed under the illumination of the LEDs. This work provides a new strategy for highly stable and efficient perovskites.
研究领域:
材料科学
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光学
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PubMed
高影响因子
OPTICS LETTERS
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2024
·Vol. 49
·期 3
·478-481
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IF 3.1
Ranran Fan,Junpeng Qiao,Jiaxin Xu,Sujuan Feng,Guangqiang Liu
Due to the superiority of low cost, easy manufacture, and tunable light emission owing to the diversity of compositions and dimensionalities, the metal halides have appeared as a promising class of semiconductors. Nevertheless, the toxicity problem along with inherent instability of Pb-based metal halides greatly limits their large-scale applications. Based on this situation, it is necessary to develop eco-friendly materials, which could simultaneously maintain the excellent optoelectronic properties of lead materials. In this Letter, the one-dimensional Cu + -alloyed Cs2AgI3 has been successfully synthesized. An intense blue emission located at 469 nm with a large Stokes shift was observed. Density functional theory calculation indicated that the Cu+ ions could effectively modulate the density of state population, which was the key factor drastically boosting the photoluminescence quantum yield (PLQY). This kind of highly efficient metal halide may overcome the bottlenecks of toxicity and poor efficiency issues of blue emission and will have a promising prospect in the optoelectronic fields.
研究领域:
材料科学
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光学
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2024
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IF 3.8
Jiazhuang Guo,Pan Zhang,Liangliang Zhu,Hao Chen,Hai-Xia Shen,Cai-Feng Wang,Su Chen
Multicolor emissive carbon dots (CDs) have received increasing attention due to their excellent optical features. By far, insufficient studies have been conducted on the preparation and modulation of multicolor CDs, and most of the precursors used for the synthesis of multicolor CDs own benzene rings. Here, we report the solvent-engineered preparation of CDs with bright multicolor emissions. The CDs are fabricated by hydrothermal/solvothermal treatment of citric acid and cyanamide, circumventing the use of precursors containing aromatic molecules as well as the medium of concentrated acids. By simply changing the reaction solvent, the emission wavelength of the CDs shifts from the blue to yellow region, and even white emissive CDs are obtained. Specifically, blue, cyan, yellow, and white emissive CDs are obtained to exhibit photoluminescence quantum yields (PL QYs) ranging from 19.7% to 62.3%. Further studies show that the bright fluorescence might originate from molecular fluorophore grafting on the CD surface. Moreover, CDs/polymer composites with uniform bright luminescence are prepared and used as fluorescent color-converting materials for fabricating multicolor LEDs. This study extends the modulated preparation of multicolor emissive CDs that are potentially useful for optoelectronic applications.
研究领域:
材料科学
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光学
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高影响因子
Journal of Materials Chemistry C
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2020
·Vol. 9
·期 6
·1983-1991
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IF 7.059
Lin Yang,Bowen Fu,Xu Li,Hao Chen,Lili Li
All inorganic perovskite quantum dots (QDs) have received great attention owing to their excellent performance in optoelectronic applications. However, they often suffer from defect-related photoluminescence (PL) quenching and phase transformation due to the loss of long-chain organic ligands, such as oleic acid (OA) and oleylamine (OAm). Here, we fabricated CsPbBr3 QDs by a one-step microwave method, in the presence of α-phase poly(vinylidene fluoride) (PVDF) acing as the surface capping ligands. The PVDF-CsPbBr3 QDs display a photoluminescence quantum yield (PLQY) of up to 98% (much higher than pristine QDs with OA/OAm as capping ligands), excellent stability in the desired cubic phase structure, and enhanced photoluminescence stability under ambient conditions. Using the as-prepared QDs as a light emitter, the efficient green perovskite quantum-dot light-emitting diode (QLED) with an external quantum efficiency (EQE) of 1.71% was prepared, exhibiting a peak luminance of 5711 cd m−2 at 516 nm. Theoretical calculations indicate that there exists a much stronger interaction between the CsPbBr3(001) surface and PVDF as compared to OA/OAm ligands, further explicating sufficient surface passivation with the introduced PVDF ligand.
研究领域:
材料科学
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光学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Yufeng Zhou,Jing Ding,Ze Wang,Yao Tong,Xiaojuan Liang,Juan Du,Wei Xia,Zhengzheng Liu,Weidong Xiang
In recent years, perovskite nanocrystals (NCs) have been considered novel and potentially valuable optical gain materials that can generate relatively low thresholds and stable stimulated emissions in various external environments. Here, for the first time, an ethylene vinyl acetate copolymer (EVA) film-protected metal halide perovskite (Cs 4 PbBr 6 ) solid powder was successfully synthesized, and its photoluminescence quantum yield (PLQY) value was as high as 61%. In addition, because the Cs 4 PbBr 6 @EVA composite film has excellent optical gain performance, this work explored the optical gain of the Cs 4 PbBr 6 @EVA composite film under 800 nm femtosecond (fs) laser excitation. The experimental results show that the Cs 4 PbBr 6 @EVA composite film has a low threshold (0.89 mJ/cm 2 ) and stable stimulated emission and generates amplified spontaneous emissions (ASEs) at 544 nm. In addition, the application of Cs 4 PbBr 6 @EVA composite film in the field of white light-emitting diodes (WLEDs) has also been studied. The color gamut of this Cs 4 PbBr 6 @EVA composite film is as high as 124.7% of the National Television Standards Committee (NTSC) 1953 standard color gamut and covers 92.8% of the Rec. 2020 standard color gamut. This work proposes a simple method to solve the problem of the poor stability of perovskite solid powder, and the prepared Cs 4 PbBr 6 @EVA composite film shows significant promise in WLED and laser applications.
研究领域:
材料科学
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光学工程
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高影响因子
CHEMISTRY OF MATERIALS
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2017
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IF 9.466
Ding Zhou,Di Li,Pengtao Jing,Yuechen Zhai,Dezhen Shen,Songnan Qu,Andrey L. Rogach
Aggregation-induced luminescence quenching of carbon dots (CDots) is the main obstacle for their applications in the solid state. Herein, we report a method to produce strongly luminescent CDots@silica composite gels with highly concentrated emitting centers, where the gelation of tetraethyl orthosilicate is initiated by the surface hydroxyl groups of CDots. The key feature of this approach is to prevent both the collision between high concentrated CDots in gelating solution and their aggregation upon drying. The resultant CDots@silica composite xerogel exhibits both high CDots loading fraction (19.2 wt %) and photoluminescence quantum yields (>40%).
研究领域:
材料科学
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光学
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高影响因子
Journal of Physical Chemistry C
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2023
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IF 3.7
Bo Zhou,Yasin Muhammad,Dong Ding,Zexiang Liu,Hanlin Hu,Ye Wang,Haizhe Zhong,Yumeng Shi,Henan Li
Multi-ion codoping strategies have been intensively studied for metal halide perovskite optical engineering. Although tunable dual broadband emissions can be achieved by pairing Sb3+/Mn2+ doping centers in metal halide hosts, there have been few reports of highly efficient light emission with a near-unity photoluminescence quantum yield (PLQY). In this study, Mn2+ dopants are incorporated into a Sb3+-doped Rb4CdCl6 system. Tunable dual emissions and a substantial increase in the PLQY from ∼60% to near-unity (98%) are achieved. Energy transfer is strong and localized and occurs only between the Sb3+ donor and the adjacent Mn2+ acceptor. The green self-trapped exciton emission (524 nm) is converted into a red d–d emission (607 nm) without changing the excitation profile. The Sb3+ optical centers without adjacent Mn2+ species maintained their original green emission. Spectroscopic and probabilistic investigations showed that the luminescent and thermally quenched Sb3+ optical centers play identical roles in the energy-transfer process, and nonradiative recombination was successfully inhibited. These findings clarify how Sb3+ and Mn2+ dopants couple in the metal halide host and facilitate the design of high-performance materials that give tunable broadband fluorescence via an energy-transfer process.
研究领域:
材料科学
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光学工程
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高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Jingyi He,Shimin Liu,Jianmin Gu,Shiqing Xu
All-inorganic lead halide perovskite quantum dots (CsPbX3 QDs, X = Cl, Br, I) glass has elicited extensive attention due to its excellent stability. However, the realization of CsPbX3 QDs glasses with a high photoluminescence quantum yield (PLQY) remains a challenging task. In this study, Eu3+ ions act as nucleating agents to promote the formation and crystallization of CsPbBr3 QDs. Rb+ ions further improve the crystallization quality and reduce the defects between CsPbBr3 QDs and the glass interface. The codoping of Eu3+ and Rb+ ions greatly improved the PLQY of CsPbBr3 QDs. The highest PLQY is achieved in the 0.33Rb-2Eu heat-treated at 500 °C–6 h, reaching 54%. Furthermore, among the light-emitting diodes (LEDs) prepared with 1Cs-0Eu, 1Cs-2Eu, or 0.33Rb-2Eu, 0.33Rb-2Eu has the highest color gamut coverage (108.9% of the National Television Standards Committee color gamut and 92.7% of Rec. 2020 color gamut at 20 mA) and the strongest durable high-power driving capability, making it an ideal material for green LEDs.
研究领域:
材料科学
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光学
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高影响因子
JOURNAL OF LUMINESCENCE
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2024
·
IF 3.3
Guang-Xuan Zhang,Qiao-Yun Yin,Bing Wang,Li-Ying Liu,Li-Yuan Chang,Ru-Zhi Wang
All-inorganic lead-containing perovskites have shown strong luminescence, but the use of lead has hindered their commercial development due to its stability and toxicity. In this paper, we propose thermal precipitation in ionic liquids (ILs) for synthesizing Bi 3+ -doped Cs 2 ZrCl 6 double perovskites (Cs 2 ZrCl 6 :Bi 3+ (ILs)), which have a better crystallinity compared to the Cs 2 ZrCl 6 :Bi 3+ (HCl) synthesized by the traditional hydrochloric acid method. Most interestingly, the Cs 2 ZrCl 6 :Bi 3+ (ILs) exhibits ultra-high photoluminescence quantum yield (PLQY) of up to 78.52%, which is about three times higher than the Cs 2 ZrCl 6 :Bi 3+ (HCl) prepared by the traditional method. In addition, the PLQY of this paper is the highest in the reported works for the Cs 2 ZrCl 6 :Bi 3+ . It has been confirmed that the high PLQY of Cs 2 ZrCl 6 :Bi 3+ (ILs) is due to the interaction force between N atoms and perovskites in ionic liquid cations, and the cations in ionic liquids can improve the crystallinity of Cs 2 ZrCl 6 :Bi 3+ (ILs) double perovskite crystallites by passivating shallow defects. The research provides an alternative and efficient method for synthesizing stable lead-free double perovskites with good optical properties.
研究领域:
材料科学
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光学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Ruoyu Dai,Xipao Chen,Ning Ouyang,Yaoping Hu
Carbon dots (CDs) with tunable photoluminescence (PL), especially with long wavelength PL , offer great potential for various applications including sensing, bioimaging, photomedicine, and optoelectronic devices. Here, we use 2,3-diaminopyridine as a single precursor to synthesize colorful CDs in different pH conditions. By simply regulating the reaction media from alkali to neutral to acid, bright CDs emitting violet, green, and orange fluorescence are prepared, respectively. Detailed characterizations reveal that the red-shift of PL is caused by the growing size of sp 2 conjugated domain and increasing content of graphite nitrogen. We embed CDs in starch to suppress self-quenching and enhance the PL quantum yields. The CD/starch composites, possessing efficient solid-state fluorescence, can be coated on the ultraviolet chips (365 nm) to fabricate multicolor light-emitting diodes toward indoor illumination. This work presents a new strategy to adjust the PL wavelength of CDs in a wide range, and clarifies the emission mechanism.
研究领域:
材料科学
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光学
·
化学
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高影响因子
ADVANCED MATERIALS
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2024
·
IF 27.4
Jiangyuan Jiang,Shuai Zhang,Qingsong Shan,Linxiang Yang,Jing Ren,Yongjin Wang,Seokwoo Jeon,Hengyang Xiang,Haibo Zeng
White light-emitting diodes (WLEDs) are the key components in the next-generation lighting and display devices. The inherent toxicity of Cd/Pb-based quantum dots (QDs) limits the further application in WLEDs. Recently, more attention is focused on eco-friendly QDs and their WLEDs, especially the phosphor-free WLEDs based on mono-component, which profits from bias-insensitive color stability. However, the imbalanced carrier distribution between red-green-blue luminescent centers, even the absence of a certain luminescent center, hinders their balanced and stable photoluminescence/electroluminescence (PL/EL). Here, an In 3+ -doped strategy in Zn-Cu-Ga-S@ZnS QDs is first proposed, and the balanced carrier distribution is realized by non-equivalent substitution and In 3+ doping concentration modulation. The alleviation of the green emitter by the In 3+ -related red emitter and the compensation of blue emitter by the Zn-related electronic states contribute to the balanced red-green-blue emitting with high PL quantum yield (PLQY) of 95.3% and long lifetime (T 90 ) of over 1100 h in atmospheric conditions. Thus, the In 3+ -doped WLEDs can achieve exceedingly slight proportional variations between red-green-blue EL intensity over time (∆CIE = (0.007, 0.009)), and high champion CRI of 94.9. This study proposes a single-component QD with balanced and stable red-green-blue PL/EL spectrum, meeting the requirements of lighting and display.
研究领域:
材料科学
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光学工程
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高影响因子
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