Entropy
·
2019
·Vol. 21
·期 2
·180
·
IF 2.419
Xiaoyi Chen,Hongbo Xu,Mengyao Pan,Jiupeng Zhao,Yao Li,Ying Song
Cracks and defects, which could result in lower reflectivity and larger full width at half maximum (FWHM), are the major obstacles for obtaining highly ordered structures of colloidal crystals (CCs). The high-quality CCs with high reflectivity (more than 90%) and 9.2 nm narrow FWHM have been successfully fabricated using a fixed proportion of a soft matter system composed of silica particles (SPs), polyethylene glycol diacrylate (PEGDA), and ethanol. The influences of refractivity difference, volume fractions, and particle dimension on FWHM were illuminated. Firstly, we clarified the influences of the planar interface and the bending interface on the self-assembly. The CCs had been successfully fabricated on the planar interface and presented unfavorable results on the bending interface. Secondly, a hard sphere system consisting of SPs, PEGDA, and ethanol was established, and the entropy-driven phase transition mechanism of a polydisperse system was expounded. The FWHM and reflectivity of CCs showed an increasing trend with increasing temperature. Consequently, high-quality CCs were obtained by adjusting temperatures (ordered structure formed at 90 °C and solidified at 0 °C) based on the surface phase rule of the system. We acquired a profound understanding of the principle and process of self-assembly, which is significant for preparation and application of CCs such as optical filters.Keywords:soft matter;colloidal crystals;self-assembly;entropy-induced
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
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
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 6
·2202128
·
IF 9
Xiaopeng Zhou,Jiejun Ren,Wenlei Cao,Andries Meijerink,Yuhua Wang
Colloidal indium phosphide quantum dots (In(Zn)P/ZnS QDs) show potential for application in the field of light emitting diodes (LED) and Mini/Micro-LEDs displays due to their tunable emission and low toxicity. However, the performance of blue-emitting indium phosphide QDs is still lagging behind that of red and green. Herein, a facile method to overcome this difficulty is proposed. The highly active Zn(ClO 4 ) 2 precursor is injected into the reaction mixture during the nucleation process to enhance zinc incorporation, which generates the In(Zn)P alloy QDs with enlarged bandgap. At the same time, the increase of zinc content can inhibit excessive growth of In(Zn)P QDs, and significantly improve its size distribution. The monodisperse In(Zn)P/ZnS QDs exhibit excellent blue emission (466 nm) and have the narrowest full width at half maxima (41 nm) of blue emission In(Zn)P QDs ever reported. This work provides a feasible and effective strategy for obtaining narrow-band blue-emitting In(Zn)P/ZnS QDs.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Xinyi Lv,Yuqin Su,Hengyang Xiang,Linxiang Yang,Xinrui Chen,Yifei Wang,Kun Zhang,Jiahao Tang,Yuhui Ye,Bo Cai,Xueying Ma,Xiaoyong Wang,Haibo Zeng
Perovskite quantum dots (PQDs) are expected to be an ideal candidate for wide-color gamut displays owing to their high color purity. However, their color purity is challenged by remarkable spectral broadening due to non-uniform size distribution and crystal defects. Here, a ligand-ion (TOP-Zn) complex-modulating nucleation strategy is proposed to depress spectral broadening. This is achieved by enhancing the steric hindrance effect during lead-halogen octahedral assembly and reducing the reaction activity/sites of the system. This strategy is universal and has been confirmed to be effective for blue, green, and red PQDs, achieving narrowed spectral full-width-at-half-maximum (FWHM) of 15, 17, and 25 nm, respectively. These FWHMs are record-breaking and contribute to a wide color gamut coverage of ≈130% National Television Standards Committee and ≈100% Rec. 2020 standard. Meanwhile, these PQD-based light-emitting diodes (PeLEDs) exhibit a high external quantum efficiency (EQE) of exceeding 20% at their pure color range. These results provide a feasible path to achieve ultra-uniform and pure-color luminescent PQDs for wide-color gamut displays.
研究领域:
材料科学
·
显示技术
·
纳米科技
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 6
·2313-2322
·
IF 4.569
Shuaishuai Yu,Zhiting Wei,Junxiao Wu,Tianli Wang,Jia Zhang,Xingliang Luo,Yanyan Li,Chuang Wang,Lei Zhao
Nowadays, near-infrared (NIR)-emitting luminescence materials with broad application prospects have drawn great attention. SrGa12O19:Cr3+ is a new type of solid light source material that emits NIR light with wide application prospects. However, the narrow full width at half maximum (FWHM) restricts its further multifunctional applications. Therefore, we propose a novel methodology to increase the FWHM by artificially adjusting the strength of the crystal field by doping Sc3+ ions. By employing Rietveld refinement results, parameters evolution and Raman spectra, Sc3+ ions are proved to successfully occupy the Ga3+ crystallographic sites. Combining the spectroscopy characteristics, it was confirmed that the FWHM was increased from 78 nm (127 977 cm−1) to 104 nm (96 739 cm−1) with the optimum quantum efficiency of 96.55%. In addition, the excellent thermal stability and unprecedented suitability to a 450 nm blue-chip indicate that it is a potential luminescent material candidate for fluorescence conversion NIR light-emitting diode (LED). Finally, the successful implementation of the night vision on vegetation, biological imaging of human tissue and food inspection for different pork portions illustrate the strong commonality of the method.
研究领域:
材料科学
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光学工程
·
生物医学工程
·
分子影像学
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光电子学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Wenbin Lin,Yi Xu,Jiyou Zhong
Near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) has been considered as a smart light source for NIR spectroscopy applications, leading to a growing need of developing broadband NIR phosphors. Herein, a new composition Zn 4 InSbO 8 :Cr 3+ phosphor with classical spinel-type structure was synthesized, which emits a broadband NIR light covering a region of 700–1200 nm with a peak centered at 860 nm under 460 nm excitation. The sample with an optimized Cr 3+ concentration possesses a full width at half maximum (FWHM) as broad as 180 nm mainly ascribing to multi crystallographic sites occupation. Moreover, the absorption efficiency (AE), internal quantum efficiency (IQE) and thermal stability were investigated to estimate the practicality. The relatively long-wavelength NIR emission produced by Cr 3+ in this spinel make it suitable for multi-functional applications. Finally, the asprepared phosphor combining with blue LED chip is used to fabricate a prototype NIR pc-LED, giving a NIR output power of 4.8 mW under 100 mA forward bias current with a photoelectric efficiency of 1.63%, showcasing the potential use of this material as a luminescent converter in the application of NIR pc-LEDs.
研究领域:
材料科学
·
光电子学
·
光子学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 42
·14787-14795
·
IF 6.4
Zhibin Chen,Lehui Liu,Feifei Yuan,Yisheng Huang,Lizhen Zhang,Zhoubin Lin
Near-infrared (NIR) emission materials have been widely used in food inspection, spectral analysis, and so on. The broader the emission band of NIR phosphors, the more the components will be detected, making the search for broadband NIR phosphors still under demand. Herein, a broadband NIR phosphor with a FWHM of 259 nm is obtained by adjusting the synthesis temperature, due to the intrinsic advantages of phase transition and microstructure diversity in the Mg2Al4Si5O18 compound. As the sintering temperature increases from 1400 °C to 1460 °C, the partial Mg2Al4Si5O18:Cr3+ sample is transformed from the low temperature phase to the high temperature phase with a broadening of the emission FWHM from 25 nm to 259 nm, which can be attributed to the longer Mg–O bond and the larger volume of the [MgO6] octahedron causing a weaker crystal field after the phase transition. A series of phosphors with different Cr3+ doping concentrations are synthesized at the optimum synthesis temperature of 1450 °C and their properties are studied in detail. The luminescence of Mg2Al4Si5O18:0.005Cr3+ decreases with the increasing temperature, and about 56% is maintained at about 150 °C and the emission peak width still remains at 251 nm. NIR phosphor-converted LEDs (pc-LEDs) with an output power of 6.82 mW and a photoelectric efficiency of 3.82% are achieved. This work provides fresh insight into the exploration of novel Cr3+ ion-based broadband NIR materials for pc-LEDs.
研究领域:
材料科学
·
光学
·
光子学
·
半导体器件
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2022
·
IF 2.719
Syed Adil Shah,Kuo-Juei Hu,Muhammad Naveed,Cao Lu,Shengyong Hu
Herein, gold-nanoclusters Au 6 (SR) 6 are synthesized in the argon atmosphere, using 2-phenylethanethiol and tetraoctylammonium bromide, as ligands and surfactants, respectively. Au 6 (SR) 6 possesses ca. 1.95 eV HOMO-LUMO gap, which is comparatively high and is also a dominant factor for quantum confinement effect. Moreover, the X-ray Photoelectron Spectroscopy (XPS) study shows the peak of Au 4f 7/2 appears at 86.89 eV, which describes the consistency regarding the size of clusters with XPS peak shift for Au 4f 7/2 value. In addition, the full width half maximum (FWHM) increases accordingly by decreasing the size of clusters.
研究领域:
纳米技术
·
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Guojun Zhou,Xingxing Jiang,Maxim Molokeev,Zheshuai Lin,Jing Zhao,Jing Wang,Zhiguo Xia
Finding new low-dimensional metal halides with broad-band emission is attracting interest in single-component phosphor for white light-emitting diodes (WLEDs). The full-spectrum white light still remains a challenge as found in the two-dimensional hybrid material (C6H18N2O2)PbBr4 exhibiting the intrinsic free exciton (FE) and broad-band self-trap exciton (STE) emission upon 365 nm ultraviolet excitation, and a combined strategy has been proposed through doping the Mn2+ ions enabling a superposition of multiple emission centers toward the ultra-broad-band warm white light. The occupation of Mn2+ in (C6H18N2O2)PbBr4 has been discussed, and optical investigations verify that the warm white-light emission of Mn2+-doped (C6H18N2O2)PbBr4 originates from the coupling effects of the FE, STEs, and the 4T1–6A1 transition of the doped Mn2+. When the concentration of Mn2+ is 5%, the emission spectrum of the phosphor covers all visible-light areas with a full width at half maximum (FWHM) of about 230 nm. The high Ra (84.9) and warm light CCT (3577 K) values of the as-fabricated WLED lamp demonstrate that (C6H18N2O2)Pb1–xMnxBr4 can be promising as single-component white-light phosphor in solid-state lighting. Our work could provide a new understanding and perspective about hybrid metal halides for designing superior phosphor toward single-component white emission.
研究领域:
材料科学
·
光电
·
固态照明
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Lianwei Fan,Ke Ding,Hongting Chen,Songpo Xiang,Rui Zhang,Runda Guo,Zhitian Liu,Lei Wang
Formamidinium (FA) lead bromide (FAPbBr 3 ) perovskite nanocrystals (P-NCs) have ultrapure green emission and high stability, while FAPbBr 3 NCs based light-emitting diodes (FA-NLEDs) still have little report. Here, FAPbBr 3 NCs with a high photoluminescence quantum yield of 85.8% were synthesized. By controlling the concentration of FAPbBr 3 NCs in toluene solution, the exciton recombination region was precisely confined to the emitting layer and the parasitic emission coming from electron transport layer disappeared, resulting in the pure green emissions. The optimized FA-NLED presents a maximum external quantum efficiency (EQE), current efficiency (CE) of 3.84% and 16.08 cd/A respectively, with the EL emission peak of 528 nm, CIE of (0.183, 0.763) and a full width of half-maximum (FWHM) of 24 nm, which is among the best performance of FA-NLEDs.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 29
·9968-9974
·
IF 7.059
Hui Xiao,Yi Wei,Peipei Dang,Shuang Liang,Ziyong Cheng,Guogang Li,Jun Lin
Perovskite nanocrystals (NCs) have aroused wide interest in the field of optoelectronics. Herein, a quantitative post-processing method is proposed to precisely alter the photoluminescence of lead halide perovskite NCs by ligand substitution using a multidentate multifunctional polymer ligand with amide, carboxylic acid and terminal double bond groups. Surprisingly, the synergistic effect of the ligand leads to a continuously blue-shifted emission over a wide visible region (∼100 nm) with increasing addition of the polymer ligand. Moreover, the full width at half maximum (fwhm) also gradually narrows, indicating the formation of a uniform particle size after the ligand surface interaction. Simultaneously, the terminal double bonds can be cross-linked with styrene to protect perovskite NCs from moisture. These results provide a new route for controllable photoluminescence regulation and preliminarily explore the correlation between the luminescence properties of perovskite NCs and polymer ligands.
研究领域:
材料科学
·
光电子学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yuzhu Pan,Xin Wang,Yuhan Liao,Yubing Xu,Yuwei Li,Qing Li,Xiaobing Zhang,Jing Chen,Zhuoya Zhu,Zhiwei Zhao,Elias Emeka Elemike,Mamoru Furuta,Wei Lei
Narrowband photodetectors (NPDs) with the capability of detecting light within a selective wavelength range are in high demand for numerous emerging applications such as imaging systems, machine vision, and optical communication. Halide perovskite materials have been developed for eliminating the current complex filtering systems in NPDs due to their beneficial properties, while currently NPDs using perovskite materials are limited by hardly fully eliminated short wavelength response, low charge collection efficiency (CCE), complex fabrication process, and so forth. Herein, a series of perovskite single-crystalline heterojunctions (PSCHs) with a structure of Bi-MAPbX3/MAPbY3 are fabricated by liquid phase epitaxy for filter-free narrowband detection. By varying the halide component in the PSCH, the PSCH-based NPDs can realize continuously tunable spectral response range from blue to NIR regions and ultra-narrow full width at half-maximum (FWHM) of <20 nm. Specifically, the PSCH-based NPD with a high CCE under a large electric filed shows a high spectra rejection ratio of >1000, a fast response speed with rise/fall time of ∼160/∼225 μs, and long-term stability more than 3 months in ambient air. This work provides a simple strategy for designing low-cost and high-performance filter-free NPDs with a tunable spectral response.
研究领域:
材料科学
·
光电子学
·
光子学
·
半导体器件
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）