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
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jie Ren,Hongbo Xia,Yue Wu,Yaqun Han,Shufen Zhang,Suli Wu
Mie resonant structural colors have recently emerged as a promising approach for large-scale and high-precision material appearance design to replace plasmonic structures. However, Mie resonant structural colors are still limited in the gamut of red because high-order multipoles such as electric and magnetic quadrupoles (EQ, MQ) usually exist in blue band when the electric dipole (ED) and magnetic dipole (MD) located in red band. Here we achieved pure red Mie resonant structural color based on ZnO spheres. Both simulation and experimental results proved that the dipole resonance and quadrupole resonance can be separated effectively by decreasing the refractive index of the resonator. By comparing different materials, ZnO is the most suitable material to generate a pure red color. Further, by controlling the distance of ZnO spheres on the substrate, high-order multipole resonance was inhibited completely and pure red Mie resonant structural color was achieved. In addition, by tuning the size of ZnO spheres, bright purple, blue, green, yellow, orange, and red colors were also realized. Finally, complex patterns can be easily made by the spraying method. This work opens new perspectives on full-color Mie resonant structural colors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-9
·
IF 14.7
Li Yanming,Deng Ming,Zhang Xuanyu,Xu Ting,Wang Ximeng,Yao Zhiwei,Wang Qiangqiang,Qian Lei,Xiang Chaoyu
Even though lead halide perovskite has been demonstrated as a promising optoelectronic material for next-generation display applications, achieving high-efficiency and stable pure-red (620~635 nm) emission to cover the full visible wavelength is still challenging. Here, we report perovskite light-emitting diodes emitting pure-red light at 628 nm achieving high external quantum efficiencies of 26.04%. The performance is attributed to successful synthesizing strongly confined CsPbI 3 quantum dots with good stability. The strong binding 2-naphthalene sulfonic acid ligands are introduced after nucleation to suppress Ostwald ripening, meanwhile, ammonium hexafluorophosphate exchanges long chain ligands and avoids regrowth by strong binding during the purification process. Both ligands enhance the charge transport ability of CsPbI 3 quantum dots. The state-of-the-art synthesis of pure red CsPbI 3 quantum dots achieves 94% high quantum efficiency, which can maintain over 80% after 50 days, providing a method for synthesizing stable strong confined perovskite quantum dots.
研究领域:
材料科学
·
光电子学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 12
·7508-7519
·
IF 4.22
Yang Xu,Zhao Xiaofan,Wang Rui,Yang Zining,Song Changqing,Yuan Maohui,Han Kai,Lan Sheng,Wang Hongyan,Xu Xiaojun
Exploiting the optical/magnetic bifunctional upconversion nanoparticles (UCNPs) with small size has become a trend in the high-resolution biological imaging. Here, we report the simultaneous size manipulation and color tuning in Er 3+ -sensitized perovskite KZnF 3 UCNPs via Mn 2+ doping. It was found that the introduction of Mn 2+ into the KZnF 3 host matrix facilitates the reduction of the nanoparticle size (from 1 μm to 50 nm). Under the excitation of both 980 and 808 nm continuous wave (CW) laser, these KZnF 3 :Er 3+ /Mn 2+ (1/x mol%) UCNPs can efficiently generate tunable upconversion luminescence (UCL) and achieve pure red UCL as the Mn 2+ concentration reaches 30 mol%. It is suggested that the energy transfer (ET) processes between Er 3+ and Mn 2+ ions contribute to the single-band red UC emission, which was well supported by investigating the dependence of UCL intensity on the pump power and the decay lifetimes of 4 S 3/2 and 4 F 9/2 states of Er 3+ ions. In addition, the KZnF 3 :Er 3+ /Mn 2+ UCNPs have been used as the T 1 -weighted magnetic resonance imaging (MRI) agents, which exhibits a high optical contrast with the background. These features make the KZnF 3 :Er 3+ /Mn 2+ UCNPs promising for excellent dual-modal agents in UCL imaging and MRI.
研究领域:
生物医学工程
·
材料科学
·
光学成像
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 16
·2337
·
IF 5.3
Kaiwang Chen,Dengliang Zhang,Qing Du,Wei Hong,Yue Liang,Xingxing Duan,Shangwei Feng,Linfeng Lan,Lei Wang,Jiangshan Chen,Dongge Ma
All-inorganic perovskite nanocrystals (NCs) of CsPbX3(X = Cl, Br, I) are promising for displays due to wide color gamut, narrow emission bandwidth, and high photoluminescence quantum yield (PLQY). However, pure red perovskite NCs prepared by mixing halide ions often result in defects and spectral instabilities. We demonstrate a method to prepare stable pure red emission and high-PLQY-mixed-halide perovskite NCs through simultaneous halide-exchange and ligand-exchange. CsPbBr3NCs with surface organic ligands are first synthesized using the ligand-assisted reprecipitation (LARP) method, and then ZnI2is introduced for anion exchange to transform CsPbBr3to CsPbBrxI3−xNCs. ZnI2not only provides iodine ions but also acts as an inorganic ligand to passivate surface defects and prevent ion migration, suppressing non-radiative losses and halide segregation. The luminescence properties of CsPbBrxI3−xNCs depend on the ZnI2content. By regulating the ZnI2exchange process, red CsPbBrxI3−xNCs with organic/inorganic hybrid ligands achieve near-unity PLQY with a stable emission peak at 640 nm. The CsPbBrxI3−xNCs can be combined with green CsPbBr3NCs to construct white light-emitting diodes with high-color gamut. Our work presents a facile ion exchange strategy for preparing spectrally stable mixed-halide perovskite NCs with high PLQY, approaching the efficiency limit for display or lighting applications.Keywords:perovskite nanocrystals;ligand assisted reprecipitation;halide-exchange;ligand-exchange;pure red emission
研究领域:
材料科学
·
纳米技术
·
光电
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Light-Science & Applications
·
2025
·Vol. 14
·期 1
·1-9
·
IF 23.4
Liu Nian,Liu Zhengzheng,Huang Yuanlong,Du Peipei,Zhang Xiang,Leng Yuxin,Luo Jiajun,Du Juan,Tang Jiang
Vacuum-deposited perovskite light-emitting diodes (PeLEDs) have demonstrated significant potential for high-color-gamut active-matrix displays. Despite the rapid advance of green PeLEDs, red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials. Here, a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites. The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield (PLQY), suppressed defects, and improved crystallinity. When implemented as active layers in PeLEDs, an external quantum efficiency (EQE) of 12.6% with an emission wavelength of 640 nm is achieved, which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs (EQE below 2%). Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward full-color perovskite displays.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 16
·2300306
·
IF 9
Wei Shen,Zhan Su,Shuo Chen,Yujun Dai,Yue Qiu,Yanfeng Chen,Jiayu Jiang,Jianbin Zhang,Yun Wang,Hao Cui,Yanxing He,Kun Cao,Bo Cai,Lihui Liu,Shufen Chen
Development of high-performance and stable pure red perovskite light-emitting devices (LEDs) promotes commercialization of perovskite. Benefiting from the quantum confinement effect, pure red CsPbI 3 quantum dots (QDs) can avoid the color drift issue for mixed halide systems. Herein, a facile temperature-dependent hot-injection method combined with low temperature gradient centrifugation is employed to prepare 5.60 ± 0.05 nm pure red QDs. The QDs exhibit 642 nm photoluminescence (PL) with 37 nm full width at half maximum, and their Commission Internationale de l'Eclairage (CIE) coordinates located at (0.708, 0.292) match well with standard pure red for Rec. 2020. The PL half-lifetime for pure red QDs solution is 210 days under ambient conditions, and both the X and Y coordinates of CIE only fluctuate within (0.002, 0.002). Finally, a simple NH 4 I post-treatment to decrease ligand length further boosts the QDs conductivity, and the pure red LED exhibits 9.4% maximum external quantum efficiency. The electroluminescence spectra exhibits a sharp peak at 645 nm, and their CIE coordinates are located at (0.707, 0.290). Furthermore, the pure red LED exhibits both good working and color stability. Its half-lifetime is 25.1 min and color drifts are only (0.002, 0.002) after 30.0 min of continuous working at 60 cd m −2 with a constant current density of 3.5 mA cm −2 .
研究领域:
材料科学
·
光电技术
·
纳米科技
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Jingshan Hou,Jie Shi,Langping Dong,Jianghua Wu,Ganghua Zhang,Haijie Chen,Wei Gao,Yongzheng Fang
The discovery of pure-red emitting phosphor is great meaningful for the achievement of high color rendering index white light emitting diodes , but still a challenge due to the strict crystal field limitations. In this work, we demonstrate the preparation of a 630 nm pure-red emitting Ca 3 Si 2 O 7 :Eu 2+ phosphor for the first time through a CO reduction strategy. The changes in crystal field strength caused by different methods for the preparation of Ca 3 Si 2 O 7 :Eu 2+ are investigated and discussed based on the understanding of the thermodynamic theory and structure resolution. Finally, a white light-emitting diode with a high color rendering index (Ra = 98) is accomplished by combining the as-prepared Ca 3 Si 2 O 7 :Eu 2+ pure-red emitting phosphor with a 375 nm chip and the commercial used blue and green phosphors. The results also demonstrate the generalizability of the weak reduction strategy for the exploration of “redder” Eu 2+ doped phosphors.
研究领域:
材料科学
·
光电子学
·
固态物理
·
无机化学
·
照明技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）