CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Jia-Kai Chen,Ju-Ping Ma,Shao-Qiang Guo,Ya-Meng Chen,Qing Zhao,Bin-Bin Zhang,Zhi-Yong Li,Yang Zhou,Jingshan Hou,Yoshihiro Kuroiwa,Chikako Moriyoshi,Osman M. Bakr,Junying Zhang,Hong-Tao Sun
Cesium lead halide perovskite nanocrystals (NCs) have emerged as promising luminescent materials for a range of applications. However, the creation of highly luminescent violet-emitting CsPbCl3 NCs mostly relies on doping of a limited number of small-sized metal ions or post-synthetic surface treatment of NCs. Alkaline-earth (AE) metals (e.g., Ca2+, Sr2+, and Ba2+) have been proposed to be able to substitute Pb2+ in halide perovskites, yet it remains incompletely understood whether AE metal ions can be incorporated into the perovskite lattice or can be merely situated at the surface. Here, we explore the possibility of using AE metal ions for the suppression of the formation of trap centers, which leads us to develop a one-pot synthetic passivation strategy to boost the violet-emitting efficiency of CsPbCl3 NCs through the creation of a Ca2+/Sr2+ involved passivation layer. The photoluminescence quantum yield of violet emission reaches 77.1% by incorporating an optimal amount of Ca2+. A wide range of optical and structural characterizations, coupled with first-principles calculations, aid in clarifying the underlying mechanism for the AE-metal-dependent passivation of CsPbCl3 NCs. Specifically, based on the experimental and theoretical results, a model is proposed for the observed abnormal incorporation phenomenon of AE2+ ions in NCs (i.e., Ba2+ can be incorporated into the core of NCs, Ca2+/Sr2+ can only be at/near the surface, while Mg2+ can neither be in the core nor at the surface). We believe that the knowledge gained here may not only offer a new perspective to obtain high-efficiency violet-emitting perovskite NCs through a one-pot synthetic passivation but can also help elucidate the functions that AE2+ ions play in the optimization of perovskite optoelectronic devices.
研究领域:
材料科学
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纳米技术
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光电
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物理化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 47
·2305858
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IF 19
Shuangyi Zhao,Zhenglin Jia,Yian Huang,Qingkai Qian,Qianqian Lin,Zhigang Zang
Lead-free metal halides have recently received sustained attention because of their nontoxicity, low-cost, as well as excellent stability and optoelectronic properties. However, most of the reported lead-free metal halides are synthesized via slow solution-processing at high temperature in toxic solvents, which may impede their commercial applications. Here, a solvent-free strategy is proposed to synthesize inorganic rubidium copper halides (Rb 2 CuX 3 , X = Cl, Br) at room temperature, which exhibit efficient violet emission dominated by a self-trapped excitons (STEs) mechanism and attractive stabilities against ultraviolet illumination and heating. Thus, Rb 2 CuX 3 powders are employed as emitters and scintillators applied in wireless light communication and X-ray imaging technologies. Under orthogonal frequency division multiplexing modulation, emitters demonstrate a broad −3 dB bandwidth of 26.3 MHz and a high received data rate of 205.1 Mbps. Additionally, flexible scintillation films based on as-prepared powders are fabricated and show outstanding X-ray scintillation properties, including a high spatial resolution of 18.1 lp mm −1 and a low detection limit of 104 nGy air s −1 , as well as promising imaging performance for irregular objects. These results suggest large-scale production of nontoxic Rb 2 CuX 3 and their potential commercialization in fields of high-speed light communication and X-ray radiography.
研究领域:
材料科学
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光电技术
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通信技术
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放射成像
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Xiang Li,Haixia Cui,Yanxi Zhong,Xiaoxi Zhou,Shuhong Xu,Shujuan Liu,Chunlei Wang
Lead halide perovskite scintillators have recently received extensive research attention owing to their short fluorescence lifetimes, low detection limits, and ease of fabrication compared to traditional scintillators. The nontoxic cerium-doped lead-free perovskites with intrinsically efficient and short lifetime d–f transitions are a prospective replacement for the toxic Pb 2+ . Here, we demonstrated Ce-doped cesium lanthanide chloride perovskites (Cs 3 LnCl 6 , Ln = Gd, Y, Lu) synthesized through a facile solution method for the first time. These perovskites exhibit blue-violet emission, which arises from Ce 5d → 4f transitions. Among three types of Cs 3 LnCl 6 perovskites, Ce:Cs 3 LuCl 6 exhibited high photoluminescence quantum yield (PLQY) of 82% and a short excited-state lifetime of approximately 34 ns. When utilized as X-ray scintillators, Ce:Cs 3 LuCl 6 crystals display a high light yield of 8120 photons per MeV and a low detection limit of 36.8 nGy air s −1 . Importantly, the figure of merit (FoM), representing the ratio of light yield to decay time, reaches 239, which is the highest reported value for lead-free perovskite scintillators up to now. Additionally, the fabrication of perovskite/PMMA films was undertaken for practical demonstrations in X-ray imaging, resulting in the attainment of a resolution of up to 8.38 lp/mm. We anticipate that this work will inspire the utilization of Ce-doped Cs 3 LnCl 6 perovskites in ultrafast scintillation applications such as high-energy physics, nuclear reaction monitoring, and dynamic X-ray imaging.
研究领域:
材料科学
·
物理学
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核科学
·
放射学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）