Materials Today Chemistry
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2021
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IF 8.301
Xiaoyong Huang,Shaoying Wang,Balaji Devakumar,Nan Ma
The development of new efficient and environmental-friendly inorganic phosphors is highly important for phosphor-converted white light-emitting diodes and optoelectronic displays. In this paper, we report a novel and simple one-step solid-state reaction to synthesize lead-free cesium copper halide Cs 3 Cu 2 Br 5 powders with bright blue emission around 460 nm. The preparation process is performed at low calcination temperatures (290–320 °C) and requires no complex apparatus, reagents, or techniques, and thus it holds great potential for mass production of halide emitters. The Cs 3 Cu 2 Br 5 powder phosphors are characterized by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence excitation and emission spectroscopy , CIE color coordinates, color purity, photoluminescence quantum yield, and temperature-dependent emission spectra . The effect of calcination temperature on the photoluminescence properties of the as-prepared Cs 3 Cu 2 Br 5 blue phosphors has been investigated and the air-stability property has also been discussed. Impressively, Cs 3 Cu 2 Br 5 blue phosphors show outstanding stability toward air exposure exceeding one month (30 days). Our work will open a new and simple approach to obtain excellent halide emitters for future solid-state lighting and displays.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Wanying Wu,Jieni Ning,Zhengheng Li,Chaoyang Lei,Qiuxue Jian,Chenzhang Gu,Zhiyao Zhou,Binli Xiao,Sheng Wu,Yinzhen Wang
Te doped Y 3 Al 5 O 12 blue-emission nanophosphors were successfully fabricated by the sol-gel method. The effects of Te doping on the structure, morphology, valence state and luminescence properties of samples were investigated using XRD, SEM, XPS and PL techniques. The results demonstrate that all diffraction peaks are in line with pure Y 3 Al 5 O 12 phase. SEM images exhibit that the prepared samples possess a uniform grain size and nearly spherical shape. The YAG:2 %Te 4+ powder sintered at 900 °C shows intense blue emission at 467 nm under 280 nm excitation, with a lifetime of 2.36 μs. These findings suggest that YAG:Te 4+ powders hold significant potential as suitable candidates for NUV-LED applications.
研究领域:
材料科学
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光学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Ziqi Nie,Lu Huang,Cewei Ren,Xinlin Xiong,Wenqing Zhu,Weiguang Yang,Linjun Wang
The facile approach combined the halide mixture of chloride and bromide anions with the exchange of short-chain ligand Phenethylamine (PEA) was used to prepare hybrid perovskite PEA-MAPbBr 3-x Cl x quantum dots (PEA-QDs-Cl), which realized blue emissive quantum dots light-emitting diode (QLED) with wider gamut of Commission Internationale de l’Eclairage (CIE) coordinates (Δx = −0.04, Δy = 0.03) than National Television Systems Committee (NTSC) TV color standard. Compared to pristine MAPbBr 3 quantum dots (pristine-QDs) prepared by conventional long-chain ligands, the size of PEA-QDs-Cl was manipulated from 9 nm to 3 nm characterized by HRTEM, emissive spectra were blue shifted from 528 nm to 469 nm measured by photoluminescence (PL). Meanwhile, time-resolved PL (TRPL) decay lifetimes of perovskite quantum dots doped with chloride anions (QDs-Cl) were improved from 10.3 ns to 13.9 ns, because short-chain ligands were introduced to passivate defects on the surface of QDs-Cl. Furthermore, XPS results showed that the chloride content was decreased from 34.7% to 33.7% through chloride vacancies on the surface of QDs-Cl were passivated by PEA.
研究领域:
材料科学
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光学工程
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纳米技术
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DOI
高影响因子
OPTICAL MATERIALS
·
2020
·
IF 2.779
Yanying Bi,Hang Yang,Xiaohan Yun,Hang Zhang,Xiangjie Ma,Guogang Li,Yujun Liang,Yongjun Chen
Currently, the development of highly efficient emission tunable phosphor materials is necessary for improving the lighting quality of UV light based white emitting diodes (WLEDs). Herein, a series of new blue-emitting Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ (CM/ZP: Eu 2+ ) phosphors were successfully synthesized through a high temperature solid phase reaction process. Interestingly, through constructing Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ solid solutions based on a complete substitution of Mg 2+ by Zn 2+ , the controllable blue-shift emission from 441 to 418 nm could be realized. This result could be attributed to the selective occupation of different Ca 2+ ions for Eu 2+ ions due to distortion of coordination polyhedron. The corresponding full width at half maximum (FWHM) exhibits a gradual narrowing from 66 to 27 nm after [Zn→Mg] replacement, and the color purity of Eu 2+ emission in Ca 7 Zn 2 P 6 O 24 (CZP) could reach 93.2%. Finally, the thermal quenching resistance of the as-prepared Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ phosphors show remarkably excellent performance. Moreover, the thermal stabilities working at 150 °C of CMZP: Eu 2+ were gradually improved from 71% for CZP: Eu 2+ to 97% for CMP: Eu 2+ of original photoluminescence intensity. Generally, the cation substation induced selective occupation of Eu 2+ to control FWHM is an efficient design to achieve emission-tunable phosphors, and the developed narrow-band Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ blue-emitting phosphors could serve as potential blue phosphors for WLEDs application.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
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IF 5.2
Miao Zhang,Jingyun Zhang,Guanguan Zhao,Guanghui Wang,Peng Liu,Huixin Li,Xiaoqiang Hou,Pengpeng Qiang,Yingjun Yang,Qingmei Su,Gaohui Du,Bingshe Xu,Hongyue Wang
Metal-halide perovskite nanocrystals (NCs) are promising semiconductor materials for the application of novel nano-optoelectronic devices and light sources , which have attracted wide attention in recent years. Many additives were applied for modulating the electronic structure, as well as improving the stability or light efficiency of the perovskite NCs, particularly the zwitterionic molecules show strong and unique interaction with perovskite lattice to passivate the defects and surface state of the perovskite NCs. Here, in this work, we synthesized the blue CsPbBr 3 perovskite NCs with the assist of zwitterionic straight-chain amino acids , and systematically studied the interaction between the perovskite and amino acids with varied molecular structure. We found that the polarization of the amino acid molecules dominates the ionized state of the two functional groups of -NH 2 and -COOH, leading to different interaction with perovskite. Eventually, the perovskite NCs with 7-aminophenic acid show stable and efficient blue light emission at peak wavelength of 475 nm with achieved light efficiency of ∼ 90%. This work demonstrated the mechanism of the interaction between series zwitterionic amino acids and perovskite experimentally, which provides a guideline for the additive selection and design.
研究领域:
材料科学
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化学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2020
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IF 4.65
Xinyi Zhang,Jian-Feng Sun
An intriguing novel perovskite-type Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with desirable properties for potential application in the field of white light-emitting diodes was first time synthesized. The Rietveld structural refinement, scanning electron microscopy and high resolution transmission electron microscopy were used to determine the crystallographic parameters, morphology and microstructure of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor. The first principle calculation based on the density functional theory further provided a theoretical understanding of the band structure for the undoped Cs 4 Mg 3 CaF 12 and indicated that it has a large direct band gap of 7.1 eV. Upon the excitation of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor in the broad range of 250–450 nm, the bright blue light emission was observed with the maximum at 474 nm and a full width at half-maximum of 2808 cm −1 that was attributed to the electric-dipole allowed 4f 6 5 d 1 →4f 7 transition of Eu 2+ ions. Based on the Dexter’s theory, the concentration quenching mechanism among Eu 2+ in the Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor was validated to be the dipole-dipole interaction, and the critical distance was determined to be 23.34 Å. On the basis of temperature-dependent luminescence measurement, an analysis of the origins of thermal quenching behavior was presented. The Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor not only has favorable thermal stability with emission intensity reduction by 20% at T = 473 K in reference to the room temperature level, but also shows the integrated PL intensity 95% as high as that of BaMgAl 10 O 17 : Eu 2+ , internal quantum efficiency of 64% and color purity of 85%. The results of this work indicate that the blue-emitting Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with promising luminescence properties has a capacity for incorporation as a component to the near-UV based phosphor-converted WLEDs.
研究领域:
材料科学
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光学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 7
·2980-2985
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IF 3.288
Zhen Li,Li Li,Huali Liu,Fei Li,Jiaqi Zhao,Yu Wang
Mn2+-doped CsPbBr3 nanocrystals (NCs) within MCM-41 mesophase silica have been prepared via a template-assisted strategy by using MCM-41 as the template. The template-synthesized CsPb1−xMnxBr3 NCs (x = 0–1) with the investigated perovskite compositions are luminescent with 465 nm pure blue light. The coprecipitation of bulk materials can be controlled by varying the amount of Mn2+ doping because the formation energy of CsPbBr3 NCs rises slightly on increasing the Mn2+ content and then decreases with the further increase in the Mn2+ content. Furthermore, they also exhibit excellent UV and air stability due to the existence of MCM-41 mesoporous silica and can be used as phosphors for solid-state lighting.
研究领域:
材料科学
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光学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jie Zhang,Aifei Wang,Dehua Wang,Qinfeng Xu,Shufang Zhang,Mingliang Liu,Mengmeng Jiao
Despite heavy research, the efficiencies of blue perovskite light-emitting diodes (LEDs) lag behind those of their green and red cousins. One of the most critical problems is the lack of technology to obtain both high blue emission and spectral stability of perovskite in thin films . Herein, we employ low-temperature synthesis of CsPbBr 3 nanoplates (NPLs) by anti-solvent assisted crystallization method using green ethylacetate anti-solvent, which show high absolute photoluminescence quantum yield (PLQY = 90.2%), blue emission at 464 nm with a narrow emission line width (15 nm), small Stokes shift (5 nm) and the average PL decay lifetime (6.91 ns). Significantly, there is no obvious QY loss at different storage conditions. Furthermore, the PL can be tuned from blue to green (457–513 nm) by controlling the amount of precursor injected into anti-solvent. For the first time, we utilize all-bromide-based inorganic perovskites to fabricate ultraviolet-pumped white LEDs (UV-WLEDs) and optimize the chromaticity coordinate of WLEDs, whose CIE color temperature (CCT) is 6083 K. Finally, highly efficient blue LED device using CsPbBr 3 nanoplates (464 nm) with high external quantum efficiency (EQE) of 2.03% was fabricated and spectral stability of CsPbBr 3 nanoplates under constant current density was demonstrated. This work will be expected to facilitate the development of the blue light source for WLEDs and displays.
研究领域:
材料科学
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光学工程
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显示技术
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 12
·2026
·
IF 5.719
Weizhuo Zhang,Xin Li,Chencheng Peng,Fei Yang,Linyuan Lian,Runda Guo,Jianbing Zhang,Lei Wang
Colloidal cesium lead halide (CsPbX3, X = Cl, Br, and I) perovskite nanocrystals (NCs) demonstrate supreme optical properties in the spectra region of infrared, red, and green. High-performance blue-emitting counterparts are still eagerly required for next-generation full-color displays. However, it is challenging to obtain efficient blue perovskite NCs, especially in a deep blue region with an emission wavelength of around 460 nm or shorter. Herein, calcium halide and ammonium ions are applied simultaneously to modify the CsPb(Br/Cl)3NCs in situ to reduce surface defects, finally remarkably enhancing the photoluminescence quantum yield (PLQY) from 13% to 93% with an emission peak at 455 nm and the Commission Internationale de l’Eclairage (CIE) coordinates at (0.147, 0.030), which is close to the requirement of the Rec.2020 standard and also meets the requirement of blue emission in DCI-P3. Bright white emission and a wide color gamut are also achieved by combining the commercial red-emitting and green-emitting phosphors. The combination of time-resolved PL spectra and femtosecond transient absorption results discloses the reason for PLQY improvement as suppressing the nonradiative recombination.Keywords:CsPb(Br/Cl)3nanocrystals;surface passivation;blue emission;ammonium ion;calcium
研究领域:
材料科学
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光电技术
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纳米技术
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产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 31
·4383-4394
·
IF 3.304
Shuangyu Xin,Miao Gao,Chuang Wang,Xuejiao Wang,Ge Zhu,Faguang Zhou,Zhuowei Li,Yuhua Wang
To explore a new family of phosphate phosphors for application in ultraviolet-based light emitting diodes (LEDs), novel promising blue emission solid solution phosphors, Ca1−xSrxHf4(PO4)6:Eu2+, with efficient and controllable photoluminescence were synthesized and characterized in the full range of 0 ≤ x ≤ 1. To deeply understand the relationship between the structure and properties of the phosphors, the phase purities, crystal structures and linear structural evolutions of Ca1−xSrxHf4(PO4)6:Eu2+ solid solutions were investigated in detail by FT-IR spectroscopy and Rietveld structure refinement of their powder XRD patterns and verified by high transmission electron microscopy (HRTEM). The linear structural evolutions induced controllable blue emission with high quantum efficiency and excellent thermal stability in the Ca1−xSrxHf4(PO4)6:Eu2+ solid-solution phosphors. Moreover, the photoluminescence properties in Ca1−xSrxHf4(PO4)6:Eu2+ can be optimized by adjusting the components. The mechanism of the controllable luminescence properties was also investigated in detail. Excellent thermal stability was obtained in Ca1−xSrxHf4(PO4)6:Eu2+, and the thermal quenching mechanism was investigated. Finally, white LEDs were fabricated and their electroluminescence properties were investigated. This simple and effective method to optimize the photoluminescence properties of phosphors can be used for designing other novel solid-solution phosphors.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 16
·9231-9239
·
IF 6.895
Xiaolin Xiao,Ye Li,Rong-Jun Xie
Low dimensional semiconductor nanomaterials show great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr3 perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr3 NPls, self-assembled into a face-to-face stacked state, had a thickness of 4.4 nm (equal to only 2 monolayers, 2 MLs) and showed a maximum emission at 437 nm and a narrow FWHM of 14 nm. The formation mechanism of the CsPbBr3 NPls by adding FeBr3 was ascribed to the constrained growth of CsPbBr3 nanocubes when the surface Cs+ ions were substituted by the protonated oleylammonium from the byproduct OLA-HBr.
研究领域:
材料科学
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纳米技术
·
光电子学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 20
·7162-7168
·
IF 5.7
Zhenghao He,Zhiqiang Bao,Xiaoyang Guo,Ying Lv,Tienan Wang,Yuejia Ma,Xingyuan Liu
Transparent displays are one of the development directions of future displays, and have great application potential in smart windows, wearable electronic products, virtual reality technology, touch screens and other fields. Perovskite materials have high fluorescence quantum efficiency and high color purity, which make a thin luminous layer achieve high device performance, making us foresee their potential application in the field of transparent displays in the future. However, due to the limitations of the modulation of the luminescent layer and top transparent electrodes, the performance of transparent perovskite light-emitting diodes (TPeLEDs) still has a certain gap compared to the traditional perovskite light-emitting diodes (PeLEDs). In this work, the first blue emitted TPeLEDs were prepared by using quasi two-dimensional perovskite materials and multilayer transparent top electrodes. By designing and optimizing the performance of the luminescent layer and the structure of the top transparent electrode, the transmittance and device efficiency of TPeLEDs were enhanced. The best TPeLED shows a maximum transmittance of nearly 70%, and displays a maximum brightness of 2294 cd m−2 and a maximum external quantum efficiency (EQE) of 11.73%.
研究领域:
材料科学
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光学工程
·
电子工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）