Advanced Optical Materials
·
2024
·Vol. 12
·期 22
·2400722
·
IF 8
Zhen-Yu Ma,Bai-Sheng Zhu,Xue-Chen Ru,Yi-Chen Yin,Li-Zhe Feng,Guan-Jie Ding,Mei-Yu Zhou,Yong-Hui Song,Hong-Min Zhou,Cheng-Ming Wang,Jing-Ming Hao,Hong-Bin Yao
Inorganic CsPbI 3 perovskite has great potential to fabricate deep-red light-emitting diodes (LEDs) owing to excellent color purity, thermal stability, and carrier mobility. However, fabricating high-quality CsPbI 3 thin films for high-performance LEDs remains challenging. While it is demonstrated that hydrogen bonds between organic ammonium cations and molecule additives can lead to high-quality organic–inorganic hybrid perovskite films, this method cannot be applied to CsPbI 3 thin films due to the absence of hydrogen bonds between Cs + ions and additives. In this study, an amorphous complex-seed-crystal growth process to fabricate high-quality γ -CsPbI 3 cuboid crystallite thin films, is reported. During the initial annealing, the metastable intermediates formed crystal nucleate seeds and transformed into amorphous complex intermediates, maintaining stability at an elevated temperature for perovskite crystallization. With prolonged annealing, the amorphous complex around the nucleate seeds gradually converts to γ -CsPbI 3 perovskite, enabling us to fabricate CsPbI 3 thin films with high crystallinity and orientation. The resulting deep-red LEDs exhibit a peak external quantum efficiency (EQE) of 16.5% and a high maximum luminance of 3158 cd m −2 . Moreover, the devices show significantly suppressed efficiency roll-off, maintaining an EQE of 14.8% even under a high current density of 500 mA cm −2 .
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
高影响因子
Optical Materials Express
·
2021
·Vol. 11
·期 2
·355-370
·
IF 3.442
Dongxun Chen,Shihai Miao,Yanjie Liang,Yanjie Liang,Yanjie Liang,Weili Wang,Shao Yan,Jianqiang Bi,Jianqiang Bi,Kangning Sun
Core-shell Bi2SiO5 nanosystem with uniform morphology and narrow size distribution has been successfully synthesized via a facile template-assisted route. With the introduction of Eu3+, detailed studies are performed to evaluate its promise as Eu3+-based phosphor host. The yielded Bi2SiO5:Eu3+ nanospheres are proven to be pure tetragonal phase via X-ray diffraction and Rietveld refinement. Moreover, the phosphor particles consist of monodisperse spheres with an average diameter of approximately 285 nm by high-resolution electron microscopy. When excited by near-ultraviolet (NUV) light, the abnormally high-intensity emission at 703 nm arising from the 5D0→7F4 transition of Eu3+ is observed. The temperature-dependent photoluminescence spectra show that the optimized Bi2SiO5:20%Eu3+ have satisfactory thermal stability with 63.7% of emission intensity at 423 K relative to 303 K. The deep-red light-emitting diode (LED) device fabricated by coating NUV chip with the Bi2SiO5:20%Eu3+ phosphors is demonstrated. The newly-developed Bi2SiO5:Eu3+ nanophosphors display commendable photoluminescence properties, demonstrating their promise as deep-red phosphor candidates for use in phosphor-converted LEDs.
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 Chemical Society
·
2022
·
IF 16.383
Qian Zhang,Yong-Hui Song,Jing-Ming Hao,Yi-Feng Lan,Li-Zhe Feng,Xue-Chen Ru,Jing-Jing Wang,Kuang-Hui Song,Jun-Nan Yang,Tian Chen,Hong-Bin Yao
All-inorganic CsPbI3 perovskite is attractive for deep-red light-emitting diodes (LEDs) because of its excellent carrier mobility, high color purity, and solution processability. However, the high phase transition energy barrier of optically active CsPbI3 black phase hinders the fabrication of efficient and bright LEDs. Here, we report a novel α-BaF2 nanoparticle substrate-promoted solution-processable heteroepitaxial growth to overcome this hindrance and obtain high-quality optically active γ-CsPbI3 thin films, achieving efficient and bright deep-red LEDs. We unravel that the highly exposed planes on the α-BaF2 nanoparticle-based heteroepitaxial growth substrate have a 99.5% lattice matching degree with the (110) planes of γ-CsPbI3. This ultrahigh lattice matching degree initiates solution-processed interfacial strain-free epitaxial growth of low-defect and highly oriented γ-CsPbI3 thin films on the substrate. The obtained γ-CsPbI3 thin films are uniform, smooth, and highly luminescent, based on which we fabricate efficient and bright deep-red LEDs with a high peak external quantum efficiency of 14.1% and a record luminance of 1325 cd m–2.
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 MATERIALS
·
2025
·
IF 26.8
Wenji Zhan,Haifei Wang,Jiahao Guo,Yugang Liang,Yanming Wang,Jixin Wu,Zhengzheng Dang,Ni Zhang,Jingjing Cao,Yingping Fan,Yu Zou,Bowei Li,Yao Wang,Yuetian Chen,Yanfeng Miao,Yixin Zhao
Deep-red light-emitting diodes (LEDs) with 690−710 nm emission show high significance in optical, agricultural, and biomedical applications. As primary candidates for deep-red emitters, all-inorganic CsPbI 3 films suffer from fused large grains with abundant trap states, leading to inferior performance of deep-red perovskite LEDs (PeLEDs). Here we report CsPbI 3 nanocrystal films with strong space confinement and notable performance at ∼700 nm of deep-red emission via bulk fabrication. The dual roles of diaza-18-crown-6 dihydriodide additive as crystallization regulator and Lewis base ligand trigger more nucleation sites, retarded grain growth and passivated trap states, ensuring the crystallization of high-quality space-confined CsPbI 3 nanocrystal films. This approach establishes a record-high external quantum efficiency (EQE) of 23.4% for deep-red PeLEDs, and achieves a maximum luminance of 10152 cd m −2 . Low roll-off is also demonstrated that EQE maintain over 20% under a high current density of 900 mA cm −2 , which is superior to state-of-the-art deep-red organic and quantum-dot LEDs. The T 50 operating lifetime is estimated to be 234 h at an initial radiance of 6.3 W sr −1 m −2 . This work provides an effectual strategy to accelerate radiative recombination and enhance the performance of CsPbI 3 -based deep-red PeLEDs.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
钙钛矿发光二极管
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）