Advanced Optical Materials
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2024
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IF 8
Siyuan Ye,Fei Lin,Linwei Peng,Jiaxin Li,Qiaohui Ruan,Zhuohan Lin,Wang Xu,Yan Li
Pure-red CsPbBr x I 3−x nanocrystals (NCs) light-emitting diodes (PeLEDs) are promising candidates for high-performance display due to their high brightness, excellent color purity and readily tunable band gap. However, achieving highly stable pure-red PeLEDs is still challenging due to phase segregation in the mixed halide CsPbBr x I 3−x NCs. Herein, pure-red mixed halide CsPbBr x I 3−x NCs with a relatively small size are synthesized using phosphate acid as a ligand, effectively avoiding spontaneous phase separation. The strong interaction between phosphate ligands and Pb 2+ facilitates the slow formation of CsPbBr x I 3−x NCs, resulting in relatively small NC sizes. In addition, a dense phosphate passivation layer forms around the surface of NCs, which imparts excellent stability to the NCs against light, moisture and heat treatment. Utilizing the highly stable CsPbBr x I 3−x NCs as an emission layer, pure-red PeLEDs emitting at 633 nm, with an external quantum efficiency (EQE) of 10.0%, a brightness of 8231 cd m −2 and a half-life of 393 min, are fabricated. Notably, the PeLEDs show excellent stability, with negligible changes in the emission spectra under an elevated bias voltage of 14 V. This work provides a new avenue for enhancing the performance of pure red PeLEDs through strongly coordinated phosphate ligand passivation.
研究领域:
材料科学
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光电技术
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产品关联
DOI
高影响因子
Nanoscale
·
2024
·
IF 5.8
Zhiqiang Ming,Siyao Li,Xinyi Luo,Siman Liu,Danliang Zhang,Xiaoli Zhu,Anlian Pan,Xiao Wang
Quasi-2D perovskites have emerged as a promising candidate material for displays owing to their high photoluminescence quantum yields and low-cost solution synthesis. However, achieving pure red quasi-2D perovskite films with luminescence centered at 630 nm and a narrow emission band presents a critical challenge for high-definition displays. Herein, by incorporating 18-crown-6 as additives that simultaneously passivate defects and regulate phase distribution, full iodine-based quasi-2D perovskite films with a single red emission peak and spectral stability are designed. Additionally, through the introduction of an appropriate amount of chlorobenzene and enhancement of annealing temperature, resulting in a narrower phase distribution, the full width at half maximum (FWHM) of the emission peak is significantly reduced. After optimization of the process, we fabricated quasi-2D perovskite films with pure red emission, which exhibited a PL peak at 627.9 nm and a narrow FWHM of 45.1 nm. Based on these pure red perovskite films, diverse complex patterns such as fluorescent anti-counterfeiting labels are implemented for data storage and information encryption. This study provides an effective approach toward developing quasi-2D perovskites with high color purity for high-definition purposes.
研究领域:
材料科学
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显示技术
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光学工程
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产品关联
DOI
PubMed
高影响因子
ACS Energy Letters
·
2021
·
IF 23.101
Lvpeng Yang,Yun Zhang,Junming Ma,Ping Chen,Yu Yu,Ming Shao
Efficient and spectrally stable pure-red perovskite light-emitting diodes (PeLEDs) are still rare and urgently needed for high-definition display. The traditional color tuning method by varying halide composition undergoes phase segregation and has spectral instability issues. Instead of halide mixing, we fabricate pure-red PeLEDs based on quasi-two-dimensional (quasi-2D) perovskites by simultaneously incorporating phenethylammonium (PEA) and 1-naphthylmethylammonium (NMA) cations. The control of PEA and NMA cospacer ratio modulates the phase distribution and the resulting different color emission. The PeLEDs with PEA:NMA molar ratio of 5:5 exhibit a pure-red (635 nm) electroluminescence (EL) with a CIE coordinate (0.709, 0.285) approaching the Rec. 2020 specification. Meanwhile, the optimized devices exhibit an external quantum efficiency (EQE) of 12.41% and a maximum brightness of 1452.6 cd m–2, which are among the best-performing pure-red PeLEDs based on quasi-2D perovskite to date. Additionally, our PeLEDs demonstrate stable EL spectra under different operating voltages and continuous operation.
研究领域:
材料科学
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光电技术
✓ 已验证
DOI
高影响因子
Small
·
2025
·
IF 12.1
Yuqin Su,Qunqing Lin,Xinyi Lv,Yan Li,Kun Zhang,Xiuting Wu,Ying Zhou,Yashuang Guo,Maria A. Sandzhieva,Sergey V. Makarov,Hengyang Xiang,Haibo Zeng
Mixed-halide perovskite plays important role in wide-color gamut displays as a vital material for three primary colors. However, halide segregation and caused unstable spectra are the intrinsic problem in mixed-halide perovskite light-emitting diodes (PeLEDs) originating from the lattice strain and the resulting defects in perovskite quantum dots (PQDs). Here, smaller transition metal cations are applied to replace Pb 2+ and release lattice strain, which avoids halogen escaping/halide vacancies forming to ensure high photoluminescence quantum yield (PLQY) and stable spectra. However, the actual doping amount is limited by ionic size and chemical environment, which will affect the improvement of optoelectronic performance. Thus, this study proposes a strategy by introducing tri-n-octylphosphine to coordinate strongly with metal cations and catch them to participate the nucleation-growth process. Through doping transition metal cations effectively, the CsPb(BrI) 3 PQDs show high PLQY (92%) and long lifetime (107.83 ns). Further, highly efficient pure-red PeLEDs with highest external quantum efficiency of 16.86% is fabricated and the spectrum can be stabilized at 630 nm with only 1 nm red-shift under bias, showing the promising potential of PQDs for next-generation display.
研究领域:
材料科学
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光电技术
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 29
·9169-9177
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IF 7.393
Rui Yang,Yan-Qing Li,Ming-Lei Guo,Xiao-Yi Cai,Jian-Xin Tang
Perovskite light-emitting diodes (PeLEDs) are promising for full-color displays due to their high color purity, low-cost and solution processability. However, pure-red PeLEDs still lag behind their green and deep-red counterparts in efficiency and brightness. Here, we employ three structurally similar dual-Lewis-base molecules ethylenediamine, ethanolamine and beta-alanine to modify the interface between the hole transport layer (HTL) and (Cs/K/PEA)PbI3-xBrx perovskite layer for efficient pure-red PeLEDs. The functional groups in these molecules can enhance the hydrophilicity on the surface of the HTL, which improves the perovskite film quality and inhibits the formation of unfavorable low-order (n = 1 and n = 2) phases. Besides, amino groups can coordinate with interfacial defects. In particular, ethanolamine and beta-alanine enable the strong film growth modulation and passivation effect due to the presence of hydroxyl and carboxyl groups. The perovskites based on ethanolamine and beta-alanine interfacial modification give rise to enhanced photoluminescence quantum yields of up to 36.5% and 34.4%, respectively. Consequently, the optimal PeLEDs achieve a pure-red emission at 634 nm with a maximum luminance of 9218 cd m−2 and a peak external quantum efficiency of 5.27%.
研究领域:
材料科学
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光电技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2024
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IF 3.3
Xinru Cheng,Yue Zhai,Xianwei Wang,Xugang Cao,Diwen Guan,Hong Zhang,Qiangqiang Zhu,Shuangqiang Fang,Le Wang
Mixed halogen CsPbI x Br 3-x nanocrystals (NCs), as indispensable materials for pure red light applications, are widely used in high-definition displays due to their excellent optoelectronic proporties. However, the traditional hot-injection synthesis requires high temperature and inert gas protection, which brings challenges for large-scale development. Herein, we propose a novel spontaneous crystallization approach to synthesize pure-red-emitting perovskite NCs at room temperature using the environmentally friendly strong polar solvent isopropanol (IPA) as an anti-solvent. Meanwhile, 3-aminopropyltriethoxysilane (APTES) surface modifier was introduced to obtain the silica coating layer through spontaneous hydrolysis reaction. The prepared CsPbI 2 Br/SiO 2 composite NCs exhibit a pure red emission peak at 632 nm with a FWHM of 32 nm and a photoluminescence QY of 44%. Furthermore, the use of APTES reduces the sensitivity of iodide ions to moisture and oxygen at room temperature, thereby suppressing phase separation of CsPbI 2 Br induced by distortion in the perovskite structure and enhancing its stability. Our work provides a meaningful approach for the batch synthesis of perovskite NCs at room temperature in environmentally friendly solvents.
研究领域:
材料科学
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纳米技术
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光电
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
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IF 5.2
Zhigang Gao,Lugui Cui,Yushi Chu,Luyue Niu,Jing Xiao,Jing Ren
In this work, rare earth ions (REs) including Yb 3+ /Er 3+ , Yb 3+ /Ho 3+ and Yb 3+ /Tm 3+ co-doped manganese oxyfluoride glasses were fabricated using melt quenching method. By fully utilizing the upconversion luminescence (UCL) of REs and regulating energy transfer between the different energy levels of RE ions and the 4 T 1 level of Mn 2+ , the output of UCL was regulated and even pure-red light can be achieved. Moreover, owing to the selective partitioning caused by phase-separation network structure in the oxyfluoride glass, the UCL intensity of glasses annealed for 72 h is significantly enhanced 58 times compared to the rapidly quenched samples.
研究领域:
材料科学
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光学
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光子学
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产品关联
DOI
高影响因子
NANO
·
2025
·
IF 1.1
Qiuhong Chen,Liyan Wu,Weiyuan Luo,Wenjian Pan,Shuang Zhang,Liping Sun,Meng Zeng
CsPbI 3 perovskite nanocrystals (NCs) are emerged as promising materials for optoelectronic devices because of their superior optical properties. However, the brightness of the deep red fluorescence does not satisfy the requirements of outdoor displays. Herein, we report an effective strategy of Zn 2+ -assisted passivation to obtain pure red fluorescence and narrow emission CsPbI 3 NCs at a modified hot-injection method. It is found that the introduced Zn 2+ ions are successfully doped into the NCs lattice to replace some Pb 2+ ions for passivating some defects, increasing the radiative recombination rate and decreasing the nonradiative recombination rate. As a result, the as-prepared Zn 2+ -treated CsPbI 3 (Zn-CsPbI 3 ) have a luminescence peak position at 635 nm and narrow full width at half maximum of only 29.8 nm, with photoluminescence quantum yield (PLQY) up to 81%, which is 30% higher than the pristine NCs. Meanwhile, the structure of the Zn-CsPbI 3 NCs is orthorhombic (γ) phases, and their morphology is a uniformly distributed hexagonal crystal system.
研究领域:
材料科学
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纳米技术
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光电子学
·
钙钛矿纳米材料
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 32
·2300116
·
IF 19
Mingyuan Xie,Jie Guo,Xiaoyu Zhang,Chenghao Bi,Xuejiao Sun,Hangren Li,Lin Zhang,David Binks,Gang Li,Weitao Zheng,Jianjun Tian
Perovskite-based light-emitting diodes (PeLEDs) with a mixed halide composition can be used to obtain the “pure red” emission, i.e., in the 620–650 nm range, required for high-definition displays. However, fast halide ion migration induces phase separation in these materials under electric fields, resulting in poor spectral stability and low efficiency. Herein, a method for producing mixed halide CsPbI 3-x Br x quantum dots (QDs) is reported in which ion migration is suppressed. The mixed halide composition is first achieved by anion exchange between CsPbI 3 QDs and hydrobromic acid (HBr), during that the bromine ions efficiently passivate the iodine vacancies of the QDs. The original oleic acid ligands are then exchanged for 1-dodecanethiol (1-DT), which suppresses halide ion migration via the strong binding of the sulfhydryl group with the QD surface. PeLEDs based on these QDs exhibit a pure-red electroluminescence (EL) peak at 637 nm, a maximum external quantum efficiency (EQE) of 21.8% with an average value of 20.4%, a peak luminance of 2653 cd m −2 , and low EQE decease with increasing luminance. The EL spectrum of these devices is stable even at 6.7 V and they have an EQE half-life of 70 min at an initial luminance of 150 cd m −2 .
研究领域:
材料科学
·
光电技术
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纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）