Journal of Physical Chemistry C
·
2021
·
IF 4.126
Meng Li,Xiao Zhang,Peng Wang,Ping Yang
Research on anion exchange reactions (AERs) indicated that the reaction rate has a significant influence on the photoluminescence properties and crystal structures of the resulting CsPb(Br/I)3 nanocrystals (NCs). Controllable AERs were achieved by controlling the reaction rate. Using controllable AERs, metastable γ-CsPbI3 NCs were directly obtained from the aged orthorhombic CsPbBr3 NCs. Rietveld refinement indicated that the crystal structure of parent CsPbBr3 was maintained without any phase transition or degradation. The prepared γ-CsPbI3 NCs exhibited good stability at room temperature. X-ray photoelectron spectroscopy analysis demonstrated the presence of Br and the high binding energy of Pb–Br bonding. Pb–Br bonds maintained the parent orthorhombic CsPbBr3 structure and increased the stability of γ-CsPbI3 NCs. Controllable AERs provide versatile methods to maintain the parent perovskite structure and synthesize CsPbI3 NCs with a more rigid crystal structure. They pave the way for the preparation of NCs, which are difficult to synthesize directly.
研究领域:
材料科学
·
化学
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DOI
高影响因子
ACS Nano
·
2023
·
IF 17.1
Jie Guo,Min Lu,Xiaoyu Zhang,Siqi Sun,Ce Han,Yu Zhang,Xuyong Yang,Stephen V. Kershaw,Weitao Zheng,Andrey L. Rogach
Orthorhombic γ-CsPbI3 possesses the highest structural stability among the optically active (light-emissive) CsPbI3 perovskites. Here, we make use of a seed-assisted heteroepitaxial growth to fabricate seed/core/shell CaIx/γ-CsPbI3/CaI2 nanocrystals. Ultrasmall CaIx nanoparticles serve as seeds to template the Pb-centered octahedral arrangement which enables the formation of the γ-CsPbI3 phase and at the same time inhibit lattice strain by blocking the force transfer that otherwise leads to an octahedral twist and so improve the structural stability of the resulting nanocrystals. An outer shell composed from the same material, CaI2, isolates the formed γ-CsPbI3 nanocrystals from the environment, which also significantly improves their stability under ambient conditions. Optical and electrical studies indicate that the seed/core/shell CaIx/γ-CsPbI3/CaI2 structure possesses a shallower set of trap states as compared to cubic α-CsPbI3 nanocrystals. Light-emitting diodes utilizing these γ-CsPbI3 nanocrystals show a record high external quantum efficiency of 25.3%, high brightness of over 13600 cd/m2, and an operational lifetime of ∼14 h before reaching 50% of their initial luminance. These devices can repeatedly be illuminated over 650 times at ∼500 cd/m2 with no decline of brightness, which indicates their great commercial potential.
研究领域:
材料科学
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光学工程
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电子工程
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DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2023
·Vol. 35
·期 12
·2210223
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IF 29.4
Jungang Wang,Yuhang Che,Yuwei Duan,Zhike Liu,Shaomin Yang,Dongfang Xu,Zhimin Fang,Xuruo Lei,Yong Li,Shengzhong (Frank) Liu
Cesium lead triiodide (CsPbI 3 ) is a promising light-absorbing material for constructing perovskite solar cells (PSCs) owing to its favorable bandgap and thermal tolerance. However, the high density of defects in the CsPbI 3 film not only act as recombination centers, but also facilitate ion migration, leading to lower PCE and inferior stability compared with the state-of-the-art organic–inorganic hybrid PSC counterpart. Theoretical analyses suggest that the effective suppression of defects in CsPbI 3 film is helpful for improving the device performance. Herein, the stable and efficient γ -CsPbI 3 PSCs are demonstrated by developing an acyloin ligand (1,2-di(thiophen-2-yl)ethane-1,2-dione (DED)) as a phase stabilizer and defect passivator. The experiment and calculation results confirm that carbonyl and thienyl in DED can synergistically interact with CsPbI 3 by forming a chelate to effectively passivate Pb-related defects and further suppress ion migration. Consequently, DED-treated CsPbI 3 PSCs yield a champion PCE of 21.15%, which is one of the highest PCE among all the reported CsPbI 3 PSCs to date. In addition, the unencapsulated DED-CsPbI 3 PSC can retain 94.9% of itsinitial PCE when stored under ambient conditions for 1000 h and 92.8% of its initial PCE under constant illumination for 250 h.
研究领域:
材料科学
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太阳能
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光伏技术
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DOI
PubMed
高影响因子
ACS Nano
·
2025
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IF 16
Yu Lou,Haoran Wang,Zhicong Zhou,Miao Zeng,Zhongliang Yan,Xueying Yang,Pengfei Fu,Arui Huang,Dong Li,Tom Wu,Yang Bai,Hui-Ming Cheng
Pure-red perovskite light-emitting diodes (PeLEDs) are critical for next-generation displays, while existing systems based on mixed Br/I compositions, quasi-2D phases, or colloidal 0D quantum dots are still facing challenges in fulfilling the requirements of the Recommendation BT.2020 (Rec. 2020) red standard. CsPbI3 nanoplatelets (NPLs) whose bandgap depends on thickness-size are a promising candidate for pure-red light-emitting emitters, but their practical use as LEDs has been hampered by the metastability of the emissive CsPbI3 cubic phase. Here, we report the synthesis of stabilized γ-CsPbI3 NPLs with a tailored surface coordination by incorporating a trace amount of dimethyl sulfoxide (DMSO) and N,N’-dimethylpropyleneurea (DMPU) into the precursor. These ligands selectively coordinate with undercoordinated Pb2+ sites in [PbI6]4– octahedra through Lewis acid–base interactions, redistributing the electron density at Pb centers and inducing lattice distortion by the Pb–I–Pb bond angle torsion, thereby stabilizing the γ-phase. The complementary effect of the polarities and the coordination capacities of DMSO/DMPU guide anisotropic growth along the [100] direction, enabling atomic-precision control of the NPL thickness (4 monolayers) to tailor the quantum-confined pure-red emission. The resultant pure-red PeLEDs achieve Commission Internationale de l’Eclairage (CIE) coordinates of (0.708, 0.292), 100% compliance with the Rec. 2020 specification, as well as an external quantum efficiency (EQE) of over 12% and a superior operational lifetime with a half-lifetime (T50) of 360 min, representing the highest reported values for CsPbI3 NPL-based PeLEDs.
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DOI
PubMed
高影响因子
Small
·
2020
·Vol. 16
·期 50
·2005246
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IF 11.459
Qiufeng Ye,Fei Ma,Yang Zhao,Shiqi Yu,Zema Chu,Pingqi Gao,Xingwang Zhang,Jingbi You
Cesium lead iodide (CsPbI 3 ) perovskite has gained great attention due to its potential thermal stability and appropriate bandgap ( ≈ 1.73 eV) for tandem cells. However, the moisture-induced thermodynamically unstable phase and large open-circuit voltage ( V OC ) deficit and also the low efficiency seriously limit its further development. Herein, long chain phenylethylammonium (PEA) is utilized into CsPbI 3 perovskite to stabilize the orthorhombic black perovskite phase (γ-CsPbI 3 ) under ambient condition. Furthermore, the moderate lead acetate (Pb(OAc) 2 ) is controlled to combine with phenylethylammonium iodide to form the 2D perovskite, which can dramatically suppress the charge recombination in CsPbI 3 . Unprecedentedly, the resulted CsPbI 3 solar cells achieve a 17% power conversion efficiency with a record V OC of 1.33 V, the V OC deficit is only 0.38 V, which is close to those in organic-inorganic perovskite solar cells (PSCs). Meanwhile, the PEA modified device maintains 94% of its initial efficiency after exceeding 2000 h of storage in the low-humidity controlled environment without encapsulation.
研究领域:
材料科学
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光伏技术
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能源研究
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DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2022
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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
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光电技术
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DOI
PubMed
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 22
·2400722
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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
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光电技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）