CHEMISTRY OF MATERIALS
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2020
·
IF 9.567
Fanghao Ye,Huijun Zhang,Pang Wang,Jinlong Cai,Liang Wang,Dan Liu,Tao Wang
CsPbX3 nanocrystal (NC)-based blue perovskite light-emitting diodes (PeLEDs) are still in a backward position while their green and red counterparts have achieved significant progress in the past few years. The emission spectrum of perovskite NCs can be manipulated via the ratio control of halides in precursor or halogen exchange of NCs. Herein, CsPbBrxCl3–x NCs are synthesized in ambient condition. With tetrabutylammonium p-toluenesulfonate (TBSA) added as the ligand during the purification process of as-synthesized perovskite NCs, bromine in NCs is substituted by chlorine and the spectrum undergoes a blue shift, whereas chlorine is exchanged by bromine in NCs and the spectrum undergoes a red shift by introducing sodium dodecylbenzenesulfonate (SDSA) as the ligand. The origin for halogen exchange can be attributed to the synergistic effects of the anion and cation of benzenesulfonates. The photoluminescence quantum yield (PLQY) of NCs increases from 7% to 81% due to the effective passivating effects of the strong ionic sulfonate heads, and the blue PeLEDs prepared by this method show a promising external quantum efficiency of 2.6%. Our work provides a new approach into spectral tuning of efficient blue PeLEDs.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
·
2026
·Vol. 14
·期 13
·e02361
·
IF 7.2
Ronghuan Liu,Sean Pan,Dingjun Wu,Bihua Hu,Zi-Wei Zheng,Hai Zhou
All-inorganic perovskite microcrystal films (MCFs) have emerged as promising candidates for next-generation optoelectronic devices due to their excellent stability and outstanding photoelectronic performance. This work presents a solvent-dynamics modulation strategy in which continuous antisolvent injection is employed to maintain a highly supersaturated precursor environment, thereby inhibiting Ostwald ripening. This approach not only prevents the dissolution of nucleation seeds and microcrystals but also enables precise control over dynamic nucleation and the directional growth of crystals. Consequently, it enables the scalable fabrication of high‑purity, highly crystalline CsPbBr x Cl 3 − x microcrystalline films with tunable thickness and composition. The resulting CsPbCl 3 microcrystal films exhibit thicknesses ranging from 12 to 47 µm and trap-state densities as low as 3.514 × 10 9 cm − 3 , approaching bulk single-crystal quality. Photoconductive detectors based on these films demonstrate excellent performance under 405 nm illumination, with a responsivity of 120 A/W, a detectivity of 1.87 × 10 1 3 Jones, and a linear dynamic range of up to 159 dB, outperforming most reported CsPbCl 3 devices. Moreover, this strategy is applicable to the synthesis of bandgap-tunable (2.20–2.90 eV) CsPbBr x Cl 3 − x microcrystal films, which exhibit an ultralow bowing parameter (b = 0.064 eV) indicative of near-ideal alloy-mixing behavior. This work provides a universal and scalable solution for solution-processed high-quality, bandgap-tunable perovskite microcrystal films, paving the way for their applications in broadband and weak-light-detection optoelectronics.
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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
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光电子学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 9
·1803-1811
·
IF 3.756
Kaiwen Hu,Yongfei Hu,Tan Li,Fen Qiao,Yunxia Chen,Jianjun Han,Lee Li,Ghafar Ali,Yi Xie
Doping Mn2+ ions into lead halide perovskite (LHP) nanocrystals (NCs) has attracted great attention in the optoelectronic fields due to the stability enhancement and unique dual-color emission characteristics arising from the energy transfer from the LHP host to the dopants (i.e., Mn2+ ions). Herein, we report a facile and scalable synthetic protocol for Mn2+-doped CsPbCl3 and CsPbBrxCl3−x nanoplates via a one-pot room-temperature (RT) procedure in the presence of hexamethyldisilazane (HMDS). It is noteworthy that both HMDS and Mn2+ ions play a critical role in triggering the crystallization of the Mn-doped LHP NCs under ambient conditions by functioning as a passivation agent with Lewis base groups that coordinate with Pb2+ ions. The optical properties including the emission wavelength and the relative PL intensity of the band-to-band emission and the Mn2+ emission are tuned by changing the amount of HMDS and the precursor ratios Mn : Pb and Br : Cl. It is interesting that the representative Mn-doped CsPbCl3 NCs displayed enhanced thermal stability, which was confirmed by the observation that the emission intensity of the sample annealed below 95 °C for 2 h increases compared with that of the fresh sample. Ion exchanges between not only Cl−, Br− and I− but also Mn2+ and Pb2+ are also investigated.
研究领域:
材料科学
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光电子学
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纳米技术
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 43
·15488-15495
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IF 7.393
Teng Li,Huijun Zhang,Cong Yu,Pang Wang,Hui Wang,Xiaoshuai Zhang,Yuandong Sun,Dan Liu,Tao Wang
Metal halide perovskite nanocrystals (NCs) are attracting increasing attention due to their potential in fabricating high-performance perovskite light-emitting diodes (PeLEDs). Compared to those of green and red PeLEDs, the performance of blue PeLEDs lags far behind, which seriously hinders the application of perovskite NCs in full-color lighting and display applications. Among the various strategies to improve the performance of blue PeLEDs based on perovskite NCs, surface ligand engineering shows great potential. Herein, amidine ligands, including acetamidine hydrochloride (AMCl), pentanimidamide hydrochloride (PMCl) and benzamidine hydrochloride (BMCl), are introduced into room-temperature synthesized CsPbBrxCl3−x NCs in air using green solvents, which are found to reduce both Cs+ and halide vacancies on the NC surface and suppress nonradiative recombination. The π-conjugated amidine BMCl can also improve the charge transport of perovskite NCs, leading to spectrally stable blue PeLEDs with a dramatically reduced turn-on voltage from 4.4 to 3.0 V, and an enhanced EQE of 2.30% and a luminance of 205 cd m−2 at 479 nm.
研究领域:
材料科学
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纳米技术
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）