FERROELECTRICS
·
2022
·
IF 0.695
Rong Tang,Jinyu Huang,Jing Liao,Jinjin Fu,Bin Deng,Gong-Guo Zhang,Ruijin Yu
A series of novel Sr3WO6:xDy3+ (0.01 ≤ x ≤ 0.35) yellow emitting phosphors are synthesized using the conventional high-temperature solid-state method. The phase analysis and optical properties are discussed in detail. Through the X-ray diffraction (XRD) analysis, the obtained phosphors are identified to be pure phases. The Sr3WO6:Dy3+ phosphors emit bright yellow emission light at 578 nm under 352 nm excitation, which is ascribed to the 4F9/2-6H13/2 transitions. The optimum doping concentration is 0.02 mol. The activation energy Ea is calculated to be 0.154 eV. The Commission International de L'Eclairage (CIE) coordinates and correlated color temperature (CCT) of the Sr3WO6:xDy3+ (0.01 ≤ x ≤ 0.35) is located in the yellow region. All results indicate that the Sr3WO6:Dy3+ phosphors have the potential to be applied in the white light-emitting diode (w-LED) field.
研究领域:
材料科学
·
光学工程
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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
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光学工程
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DOI
高影响因子
ADVANCED MATERIALS
·
2026
·
IF 29.1
Hongkang Xu,Tianle Fan,Zihao Zhu,Alim Abdurahman,Boning Wu,Wenming Tian,Jonghee Yang,Wenzhe Li,Meiqin Xiao,Simin Gong,Ping Chen
Quasi-2D metal halide perovskites (MHP) have emerged as promising candidates for light-emitting diodes (PeLEDs) due to their intrinsic advantages in color purity, bandgap tunability, and stability. The prime working principle realizing high radiative emission in quasi-2D MHP is the ultrafast, consecutive charge transfer (CT) process toward the low-bandgap crystallites across multiple quantum wells, called charge carrier funneling. Ironically, such a key process is intrinsically limited in the quasi-2D MHP by the molecular spacers, which have electronically insulating natures. To challenge this limit, herein, we explore the impact of a judiciously designed, stable, and conductive organic radical, (5H-pyrido[3,2-b]indole-2,6-dichlorophenyl)bis(2,4,6-trichlorophenyl)methyl as a molecular additive in the MHP matrix. It is found that the spatially delocalized singly occupied molecular orbital offers an electronic bridge accelerating interfacial CT and the carrier funneling by surface adsorption, thus maximizing radiation recombination yield. As a result, the radical-incorporating PeLEDs (peaking at ≈ 684 nm) achieve a remarkable external quantum efficiency of 26.8% with an operational half-lifetime of ≈ 340 min, ranking among the best deep-red devices reported to date. This work demonstrates that rational radical molecular design offers a powerful route to resolve intrinsic CT limitations in quasi-2D MHP, unlocking both high efficiency and long-term stability in next-generation PeLEDs.
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DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 43
·16639-16647
·
IF 4.569
Yifei Liu,Yifeng Liu,Meihua Wu,Can He,Qiyun Liu,Ximing Huang,Xin Min,Zhaohui Huang,Hui Wang,Ruiyu Mi
Recently, blue-emitting phosphors have attracted great interest due to their application in full-spectrum white light illumination. In this paper, a novel blue-emitting MgAl2Si4O6N4:Eu2+ phosphor was successfully synthesized through the solid-state reaction method in a reducing atmosphere. Under the excitation of near-ultraviolet (n-UV) light, the MgAl2Si4O6N4:0.02Eu2+ phosphor effectively emits a broad blue emission band centered at 456 nm with the FWHM as large as 81 nm. With the increasing Eu2+ concentration, the emission bands of MgAl2Si4O6N4:Eu2+ shift to a shorter wavelength and the FWHMs broaden gradually. Moreover, the MgAl2Si4O6N4:0.02Eu2+ phosphor exhibits a slight thermal quenching at a higher temperature. After fabricating the as-prepared MgAl2Si4O6N4:0.02Eu2+ phosphor into a white LED device, the intense neutral white light emission is obtained with excellent CRI (87.4) and CCT (5645 K). These results suggest that the blue MgAl2Si4O6N4:Eu2+ phosphor is a promising candidate in n-UV excited white LEDs.
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Xiaoman Li,Ruijin Fan,Pengfei Zhai,Xinyu Liu,Huijun Liu,Shitong Xu,Rongfei Wei,Hai Guo
The demands for white-light-emitting materials are becoming more and more rigorous. In this work, a novel kind of Sn 2+ /Mn 2+ doped phosphate aluminum calcium glass was fabricated by a traditional melt-quenching technique. Broadband excitation and emission of Sn 2+ ions were detected in Sn 2+ single-doped glass samples. By the modulation of excitation wavelength, tunable broadband cyan-blue light emissions of Sn 2+ were also realized. Combined with the red light emitting of Mn 2+ ion, a nearly white light with a good chromaticity coordinate (0.339, 0.298) and a relatively low correlated color temperature (CCT) of 5107 K were obtained in Sn 2+ /Mn 2+ codoped glasses due to the energy transfer process from Sn 2+ to Mn 2+ ions. In addition, after two cycles of heating and cooling treatment, the emission intensity of Sn 2+ doped glass sample remained 97.9% of the initial emission intensity at 300 K. All of these results reveal that these Sn 2+ /Mn 2+ doped aluminum calcium phosphate glasses have good resistance to thermal impacts and have prospects in white-light-emitting diodes (W-LEDs) fields.
研究领域:
材料科学
·
光学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 35
·12308-12313
·
IF 7.059
Ying Tang,Wenqian Cao,Lijia Yao,Yuanjing Cui,Yang Yu,Guodong Qian
Encapsulating luminescent dyes in metal–organic frameworks (MOFs) for white-light illumination and displays has received tremendous attention in recent years due to the unique colour-tuning flexibility and designability. However, the luminescent dyes may suffer from degradation due to moisture and oxygen under operating conditions. The stability and reliability of dye-encapsulated MOF phosphors remain challenges to be addressed. Herein, a broadband-emitting MOF phosphor is prepared via an ambient self-assembly process with pyrromethene 546 (pm546), pyrromethene 605 (pm605) and sulforhodamine 101 (SRh101) simultaneously confined in porous nanoscale zeolitic imidazolate framework-8 (ZIF-8). The photostability and thermostability of the pristine phosphor are evaluated in detail. By further coating it with thermoplastic polyurethane (TPU), the relative fluorescence intensity of the pristine phosphor is remarkably enhanced by 52.54%. A highly-stable remote-type incandescent white-lighting device is fabricated with a 460 nm blue LED chip with CIE chromaticity coordinates of (0.465, 0.413), a correlated colour temperature (CCT) of 2642 K and a colour rendering index (CRI) of up to 85.
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
NATURE
·
2025
·Vol. 641
·期 8062
·352-357
·
IF 48.5
Song Yong-Hui,Li Bo,Wang Zi-Jian,Tai Xiao-Lin,Ding Guan-Jie,Li Zi-Du,Xu Huaiyu,Hao Jing-Ming,Song Kuang-Hui,Feng Li-Zhe,Hu Ya-Lan,Yin Yi-Chen,Zhu Bai-Sheng,Zhang Guozhen,Ju Huanxin,Zheng Guanhaojie,Hu Wei,Lin Yue,Fan Fengjia,Yao Hong-Bin
Metal-halide perovskites are promising light-emitter candidates for next-generation light-emitting diodes (LEDs) 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 . Achieving high brightness and efficiency simultaneously in pure-red perovskite LEDs (PeLEDs) is an ongoing goal 9 , 10 . Three-dimensional (3D) CsPbI 3- x Br x emitters have excellent carrier transport capability and high colour purity, which could allow efficient and ultrabright pure-red PeLEDs. However, such devices are prone to efficiency roll-off, resulting in low efficiency and low brightness under high current density. Here, by using electrically excited transient absorption spectroscopy, we discovered the efficiency roll-off was induced by hole leakage. Therefore, we developed a CsPbI 3- x Br x intragrain heterostructure containing narrow bandgap emitters and wide bandgap barriers to confine the injected carriers. The wide bandgap barrier was incorporated by introducing strongly bonding molecules into the [PbX 6 ] 4− framework to expand the 3D CsPbI 3- x Br x lattice. This strategy resulted in bright and efficient pure-red PeLEDs, with a high brightness of 24,600 cd m −2 , maximum external quantum efficiency of 24.2% and low efficiency roll-off, maintaining a 10.5% external quantum efficiency at a high luminance of 22,670 cd m −2 .
研究领域:
材料科学
·
光学工程
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DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Ting Gong,Tongtong Xuan,Wenhao Bai,Haorui Dong,Kai Huang,Rong-Jun Xie
Quantum dot (QD)-converted micrometer-scale light-emitting diodes (micro-LEDs) are regarded as an effective solution for achieving high-performance full-color micro-LED displays because of their narrow-band emission, simplified mass transfer, facile drive circuits, and low cost. However, these micro-LEDs suffer from significant blue light leakage and unsatisfactory electroluminescence properties due to the poor light conversion efficiency and stability of the QDs. Herein, the construction of green and red QD luminescence microspheres with the simultaneously high conversion efficiency of blue light and strong photoluminescence stability are proposed. These luminescence microspheres exhibit high external photoluminescence quantum yields exceeding 46% under 450 nm excitation, along with excellent reliability against blue light, heat, and water-oxygen degradation, owing to the waveguide and spatial confinement effects of the microspheres. The microsphere-based green and red micro-LEDs achieve world-record external quantum efficiencies of 40.8% and 22.1%, respectively, and high brightness values of 1.7 × 10 8 and 7.6 × 10 7 cd m −2 , respectively. Finally, 0.6 inch red, green, and blue monochrome micro-LED displays are demonstrated by integrating microsphere-converted micro-LED arrays with thin-film transistor backplanes, which show a pixel resolution as high as 1700 PPI and brightness exceeding 10 000 cd m −2 .
研究领域:
材料科学
·
光电技术
·
显示技术
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产品关联
DOI
PubMed
高影响因子
NATURE
·
2024
·Vol. 631
·期 8019
·73-79
·
IF 50.5
Kong Lingmei,Sun Yuqi,Zhao Bin,Ji Kangyu,Feng Jie,Dong Jianchao,Wang Yuanzhi,Liu Zirui,Maqbool Shabnum,Li Yunguo,Yang Yingguo,Dai Linjie,Lee Wanhee,Cho Changsoon,Stranks Samuel D.,Friend Richard H.,Wang Ning,Greenham Neil C.,Yang Xuyong
Light-emitting diodes (LEDs) based on metal halide perovskites (PeLEDs) with high colour quality and facile solution processing are promising candidates for full-colour and high-definition displays 1 , 2 , 3 , 4 . Despite the great success achieved in green PeLEDs with lead bromide perovskites 5 , it is still challenging to realize pure-red (620–650 nm) LEDs using iodine-based counterparts, as they are constrained by the low intrinsic bandgap 6 . Here we report efficient and colour-stable PeLEDs across the entire pure-red region, with a peak external quantum efficiency reaching 28.7% at 638 nm, enabled by incorporating a double-end anchored ligand molecule into pure-iodine perovskites. We demonstrate that a key function of the organic intercalating cation is to stabilize the lead iodine octahedron through coordination with exposed lead ions and enhanced hydrogen bonding with iodine. The molecule synergistically facilitates spectral modulation, promotes charge transfer between perovskite quantum wells and reduces iodine migration under electrical bias. We realize continuously tunable emission wavelengths for iodine-based perovskite films with suppressed energy loss due to the decrease in bond energy of lead iodine in ionic perovskites as the bandgap increases. Importantly, the resultant devices show outstanding spectral stability and a half-lifetime of more than 7,600 min at an initial luminance of 100 cd m −2 .
研究领域:
材料科学
·
光电技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NATURE
·
2025
·
IF 48.5
Wu Qianqian,Cao Fan,Yu Wenke,Wang Sheng,Hou Wenjun,Lu Zizhe,Cao Weiran,Zhang Jiaqi,Zhang Xiaoyu,Yang Yingguo,Jia Guohua,Zhang Jianhua,Yang Xuyong
The electroluminescence performance of heavy-metal-free blue quantum dot (QD) light-emitting diodes (QLEDs) is much lower than that of state-of-the-art cadmium-based counterparts. Ecofriendly ZnSeTe QDs are an ideal alternative to cadmium-based blue QDs 1 , 2 , but face issues with colour impurity and inferior stability caused by the aggregated tellurium (Te n ≥2 ) that dominates compositional inhomogeneity 3 , 4 . Here we developed an isoelectronic control strategy using congeneric sulfur coordinated with triphenyl phosphite (TPP-S) to construct homogeneous ZnSeTeS QDs with pure-blue emissions and near-unity photoluminescence quantum yield. TPP with low electron-donating capability promotes the reactivity balance among anionic precursors, favouring the growth of QDs with uniform composition. The acceptor-like S with high electronegativity weakens the hole localization of the Te atoms by interfering with their surrounding carriers, thereby suppressing the formation of Te n ≥2 isoelectronic centres. Furthermore, the congeneric S increases the configurational entropy of the QDs and eliminates the stacking faults and oxygen defects, leading to improved structural stability and reduced non-radiative carrier density. Consequently, the resulting pure-blue QLEDs based on core–shell ZnSeTeS/ZnSe/ZnS QDs emitting at 460 nm show a high external quantum efficiency of 24.7%, a narrow linewidth of 17 nm, and long operational half-lifetime ( T 50 ) close to 30,000 hours at 100 cd cm −2 , rivalling state-of-the-art cadmium-based blue QLEDs.
研究领域:
材料科学
·
光电工程
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DOI
PubMed
高影响因子
ORGANIC ELECTRONICS
·
2021
·
IF 3.721
Xiaowen Zhou,Yu Zhao,Wenzhe Huang,Yuanyuan Wu,Zhongen Wu,Gufeng He
Perovskite lighting-emitting diodes (PeLEDs) with inverted structure have been considered as promising display technology due to their suitable driving schemes with n-type thin-film transistors. However, the defects and imbalanced charge carriers in the CsPbBr 3 nanocrystal (NC) PeLED are key hurdles, limiting the performance. Herein, we have successfully doped Zn 2+ ions into CsPbBr 3 NCs by ligand-assisted reprecipitation method, exhibiting an 85% enhancement of the photoluminescence quantum yield (PLQY). In addition, the optimized energy level alignment via Zn doping facilitates the carrier balance in the devices, improving the efficiencies. The obtained CsPbBr 3 :Zn-based PeLED reaches a high luminance of 3124 cd/m 2 and a maximum external quantum efficiency (EQE) of 0.85%, which are superior to those of CsPbBr 3 -based PeLED (luminance = 564 cd/m 2 , EQE = 0.09%). The results demonstrate that Zn doping significantly enhances the performance of PeLED, which increases the potential of these inverted PeLEDs connected with n-type TFTs towards practical applications.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
高影响因子
Science Bulletin
·
2021
·
IF 11.78
Fengjuan Zhang,Jizhong Song,Bo Cai,Xi Chen,Changting Wei,Tao Fang,Haibo Zeng
Voltage loading-induced change in the electroluminescence (EL) wavelength of mixed halide perovskite light-emitting diodes (PeLEDs), so-called color-shift, has become an inevitable phenomenon, which is seriously unfavorable to their applications in lighting and display. Here, we achieve color-stable blue PeLEDs via a hydrogen-bonded amine-group doping strategy. Selecting guanidine (GA) or formamidinium (FA) as amine-group (−NH 2 ) doping source for CsPbBr x Cl 3− x quantum dots (QDs), experimental and theoretical results reveal that the strong N−H⋯X (X = Br/Cl) bonding can be produced between −NH 2 dopants and Pb−X lattices, thereby increasing the migration barrier of halide anions. Resultantly, color-stable sky-blue devices were realized with emission peaks fixed at 490.5 (GA) and 492.5 (FA) nm without any obvious shift as the voltage increases, in sharp contrast devices without N−H⋯X producing a 15 nm red-shift from 487 to 502 nm. Not only that, maximum external quantum efficiency is improved to 3.02% and 4.14% from the initial 1.3%. This finding offers a convenient boulevard to achieve color-stable PeLEDs with high efficiency.
研究领域:
材料科学
·
光电子学
·
纳米技术
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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）