Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 7
·2530-2538
·
IF 7.393
Yao Tong,Mengfeifei Jin,Ya Chen,Yi Zhao,Haisheng Yang,Qin Wang,Lanlan Zhai,Xiaojuan Liang,Weidong Xiang
Lead halide perovskite CsPbX3 (X = Cl, Br, and I) nanocrystals (NCs) are widely used in the newest generation of lighting display equipment because of their excellent optical properties. However, their poor stability remains an urgent issue to overcome. Encapsulation has become a significant and effective strategy to promote the stability of perovskite NCs, particularly by the package coating of polymer and porous materials. Herein, a simple two-step encapsulation strategy is adopted to fabricate CsPbBrI2@zeolite/PMMA composite films to replace the previous preparation methods of perovskite films. A highly efficient and stable red-emitting material with great colour purity and excellent PLQY of ∼53.9% is manufactured by this simple and effective packaging method. Furthermore, because of the first-encapsulation with zeolite, the CsPbBrI2@zeoite/PMMA composite films not only reduced the agglomeration of NCs but also obtained better optical performance and environmental stability compared to that of pure CsPbBrI2/PMMA. Ultimately, WLEDs constructed by the red-emitting CsPbBrI2@zeolite/PMMA composite material achieve an outstanding colour rendering index, luminous efficiency and correlated color temperature (CRI = 94.5, LE = 77.22 lm W−1 and CCT = 5354 K), and realize tunable colour coordinates of (0.3359–0.32912, 0.3455–0.3336) in the white light area, implying that CsPbBrI2@zeolite/PMMA is very promising for obtaining a high CRI of WLEDs instead of traditional phosphor. The facile two-step encapsulation method proposed in this study provides a prospect for obtaining high-quality perovskites.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Qiurui Han,Wenjun Xu,Chunyu Ji,Gaoyang Xiong,Changsheng Shi,Dongming Zhang,Wenquan Shi,Yuxiang Jiang,Zhili Peng
The preparation of multicolor and white light-emitting carbon dots (CDs) is of both significant importance and challenging for their applications as white phosphors for light-emitting diodes (LEDs). In this report, a facile reaction system that is capable of preparing both multicolor and white light-emitting CDs was disclosed. In this system, three CDs emitting yellow, red, and green lights were prepared, and monochromatic LEDs were constructed using these multicolor CDs. Most importantly, single-component white light-emitting CDs with CIE coordinates of (0.33, 0.33) were also prepared. The white light-emitting CDs were applied as single-component white phosphors for the fabrication of white LEDs. The white LEDs constructed demonstrated excellent performance, emitting warm white light (CCT = 3723 K) with CIE coordinates of (0.39, 0.37) and an extremely high color-rendering index of 91.5, which should find favorable applications for indoor illumination.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 6
·2721-2729
·
IF 3.784
Xianju Zhou,Jie Zhang,Lingni Chen,Yanhong Li,Guotao Xiang,Sha Jiang,Li Li,Xiao Tang,Zhongmin Cao,Guangxin Xie
A series of novel red emission phosphors Sr 3 Lu 1- x (VO 4 ) 3 : x Eu 3+ ( x = 0.007, 0.009, 0.02, 0.04, 0.06) were synthesized successfully by traditional high-temperature solid-state reaction. The results of X-ray diffraction (XRD) reveal the doped Eu 3+ ions have replaced the lattice sites of Lu 3+ ions. The diffuse reflectance spectra illustrate the energy gap of Sr 3 Lu(VO 4 ) 3 host is 3.61 eV. The room-temperature steady-state fluorescence spectra show that these phosphors can be effectively pumped by the charge-transfer band (CTB) of the host in near ultraviolet (NUV) spectral region and then produce strong and pure red emission at 615 nm originated from 5 D 0 → 7 F 2 electric dipole transition of Eu 3+ . The Commission Internationale de L’Eclairage (CIE) coordinates of Sr 3 Lu 0.96 (VO 4 ) 3 :0.04Eu 3+ are (x = 0.65, y = 0.35), which are very close to the red standard of National Television Standards Committee NTSC (0.67, 0.33). The fabricated warm white-light-emitting diodes (LED) demonstrate high color-rendering index Ra as 93. The results imply the red-emitting Sr 3 Lu(VO 4 ) 3 :Eu 3+ phosphors could be potentially utilized in the fields of solid-state lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
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
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2021
·
IF 3.712
Jiannan Jia,Mengting He,Jun Wan,Yuting Zhang,Hai Guo,Xianping Fan,Xusheng Qiao,Shiguo Chen
With narrow red photoluminescence (PL) bands, tetravalent Mn 4+ doped phosphors show promising prospect in commercial application to effectively expand color gamut of phosphor converted LED displays. Here, we report a type of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ phosphors with regular cage-like micro-spherical morphologies. The micron size spherical precursors were synthesized with a propylene oxide (PO) driven fast sol–gel method. The cage -like spherical morphology is beneficial to efficiently trapping much incident light to enhance the PL of the phosphors. Being calcined at 1300 ° C, Sr 2 MgAl 21.978 O 36 :0.022Mn 4+ only exhibits the internal quantum efficiency (IQE) of 24.91%. With the Mg 2+ -Mn 4+ codoping and Y 3+ /Sr 2+ substituting strategies, to fulfill charge balance and produce John-Teller distortion, IQE of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ can be further improved up to 36.45%. The CIE color coordinates of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ under near ultraviolet excitation can be stably fixed to (0.723, 0.227) at deep red region. It thus finds a potential application as pc-LED display with much broader color gamut than that of the NTSC standard. Therefore, Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ micron size spheres can be employed as promising red phosphors for high performance LED displays.
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
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 1
·124-129
·
IF 2.019
Niu Pengfei,Liu Xiaohua,Wang Yiru,Zhao Weiren
Ba 2 LaV 3 O 11 :Eu 3+ phosphors were firstly synthesized by the traditional solid-state reaction method at 1100 °C. Their luminescence properties were investigated by photoluminescence excitation and emission spectra. The excitation spectrum shows a broad band centered at about 275 nm in the region from 200 to 370 nm, which is attributed to an overlap of the charge transfer transitions of O 2− → V 5+ and O 2− → Eu 3+ . The phosphors exhibit the red emissions of Eu 3+ and the emission intensity ratio of 5 D 0 → 7 F 2 to 5 D 0 → 7 F 1 is dependent on the Eu 3+ concentration due to an environment change about Eu 3+ ions. Concentration quenching occurs at 30 mol% in the phosphors and exchange interaction is its main mechanism. Ba 2 LaV 3 O 11 :Eu 3+ displays tunable CIE color coordinates from yellow orange to red depended on Eu 3+ content, which may have a potential application for illuminating and display devices.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
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
RSC Advances
·
2019
·Vol. 9
·期 72
·42430-42437
·
IF 3.049
Shangxuan Huang,Sen Yang,Qi Wang,Ruirui Wu,Qiuju Han,Wenzhi Wu
Cs4PbBr6/CsPbBr3 perovskite composites are fabricated by room-temperature one-pot mixing synthesis, which is short in time, free from inert gases and delivers a high product yield. Temperature-dependent photoluminescence shows that a larger exciton binding energy of 291.1 meV exhibits better thermal stability compared with that of pure Cs4PbBr6 and CsPbBr3 materials. The CIE chromaticity coordinates (0.1380, 0.7236) of green LEDs designed with Cs4PbBr6/CsPbBr3 perovskite composites show almost no variation under driving current changing from 5 to 30 mA. Furthermore, the ground Cs4PbBr6/CsPbBr3 perovskite composites mixed with red emitting K2SiF6:Mn4+ phosphor are dropped and casted on a blue-emitting InGaN chip. The white light emitting diodes (WLEDs) are presented, which have good luminous efficiency of 65.33 lm W−1 at 20 mA, a correlated color temperature of 5190 K, and the white gamut with chromaticity coordinate of (0.3392, 0.3336). According to the state of art, these excellent characteristics observed are much superior to the reported results of conventional perovskite-based WLEDs, which demonstrate the immense potential and great prospect of Cs4PbBr6/CsPbBr3 perovskite composites to replace conventional phosphors in lighting devices.
研究领域:
材料科学
·
光学工程
·
半导体技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Pengjun Zhang,Yifei Xu,Shuwei Hao,Chongqiang Zhu,Chunhui Yang
The conventional random co-doping of Tb 3+ and Eu 3+ leads to spatial separation that severely limits energy transfer efficiency between these ions, which is critical for minimizing non-radiative losses in white LEDs. To address the limitation, we designed BaTb 4- x Si 3 O 13 : x Eu 3+ , breaking through the bottleneck by occupying Tb 3+ sites with Eu 3+ . Rietveld refinement and ionic radius analysis confirmed site occupancy selectivity, enabling 71.59 % Tb 3+ →Eu 3+ energy transfer efficiency, which is higher than conventional random doping systems. Under 380 nm excitation, the phosphor yielded red emission with CIE coordinates of (0.6153,0.3838) and 86.64 % color purity, and exhibited exceptional thermal stability with 70 % intensity retention at 473 K. Fabricated wLEDs using a NUV chip with commercial blue phosphor, green phosphor, and the developed phosphor produced warm white light with a correlated color temperature of 4519 K and CIE coordinates of (0.3478, 0.3868), achieving a high color rendering index of 87.4. These results demonstrate BaTb 4 Si 3 O 13 :Eu 3+ as a highly promising red phosphor candidate for solid-state lighting applications.
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Jiang Wu,Haowen Bai,Wenjie Qu,Guanying Cao,Yanjie Zhang,Jingjie Yu
CsPbBr 3 quantum-dot borosilicate microcrystals and Eu 3+ -doped CsPbBr 3 quantum-dot microcrystals with different concentrations of Eu 3+ are successfully prepared by high temperature melting. The particle morphology of the microcrystals is characterized by scanning electron microscopy (SEM). The fluorescence characteristics are analyzed by fluorescence spectroscopy and CIE chromaticity coordinates . In this research, CsPbBr 3 quantum dots are effectively coated with borosilicate microcrystals to improve the stability of CsPbBr 3 quantum dots while ensuring its strong green emission at 517 nm. The energy transfer from CsPbBr 3 quantum dots to Eu 3+ occurs after doping. When changing the concentration of Eu 3+ , the emission peaks of perovskite broaden and blue shift occurs (517 nm→474 nm). The CIE color coordinate moves from (0.0807, 0.7200) to (0.4537, 0.2724). Therefore, the continuous adjustment of solid perovskite materials from green light to blue light and then to red light region is realized.
研究领域:
材料科学
·
纳米光学
·
无机非金属材料
·
光电子学
·
发光材料
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Pu Fan,Zefeng Xu,Qi Luo,Zongjie He,Yuhui Chen,Qiqi Miao,Cong Huang,Xiaoguang Liu,Ling Li
Phosphor-converted white LEDs are realized by combining blue InGaN chips with yellow and red emitting materials. Due to the lack of efficient red phosphor materials, we can design a broadband yellow phosphor material containing as many red components as possible. We found an abnormal broadband yellow-emitting Ba 2 CaB 2 Si 4 O 14 :Eu 2+ borosilicate phosphor inspired by natural minerals, which has been synthesized by traditional high temperature solid-state method. The structural information and photoluminescence characteristics of Ba 2 CaB 2 Si 4 O 14 :Eu 2+ were characterized in detail, and applied to the fabrication of white LED devices. Excited by near ultraviolet light at 365 nm, it displays a wide emission band from 400 to 800 nm centered on the 595 nm peak. White LED devices were fabricated by physically mixing the yellow phosphor Ba 2 CaB 2 Si 4 O 14 :Eu 2+ and synthesized blue phosphor BaMgAl 10 O 17 :Eu 2+ with 365 nm UV chip as excitation. The correlation color temperature (CCT) value and the chromaticity coordinates of the fabricated WLED devices were found to be 5522 K and (0.3293, 0.3036) respectively. In conclusion, Ba 2 CaB 2 Si 4 O 14 :Eu 2+ has great potential in the preparation of near UV excited white LEDs.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Feiyan Xie,Junqiang Gu,Dekang Xu,Qiancheng Xiong,Jinyu Yang,Xiangjian Ou,Dawei Wen
Research into red phosphors with a high color rendering index is particularly compelling, given the absence of a red component in the spectrum of commercial pc-WLEDs, which combine blue LED chips with yellow-emitting YAG:Ce3+ phosphors. Herein, we reported a novel Eu3+ activated Ca3Zn3Te2O12 red-emitting phosphor, synthesized using a conventional high-temperature solid-phase method. The phase and crystal structures were analyzed by powder X-ray diffraction and Rietveld refinement. The optimal excitation peak of the Ca3Zn3Te2O12:Eu3+ phosphor was located at 395 nm, matching those of conventional commercial near-ultraviolet chips. In addition, the Ca3Zn3Te2O12:9%Eu3+ phosphor exhibited good thermal stability, with an activation energy of 0.267 eV, and the CIE color coordinates hardly changed with temperature. Ultimatel, a high-quality white LED device was fabricated by combining Ca3Zn3Te2O12:9%Eu3+ red phosphor, a commercial BaMgAl10O17:Eu2+ blue phosphor, and(Ba,Sr)2SiO4:Eu2+ green phosphor with a 395 nm near-UV chip. Despite a substantial increase in the input current from 20 to 320 mA, the white-LED maintained a stable color rendering index of around 80, highlighting its consistent performance. These results indicated that Eu3+ activated Ca3Zn3Te2O12 phosphors are promising red emission candidates for white LEDs pumped by near ultraviolet chips.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 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）