NANOTECHNOLOGY
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2024
·Vol. 35
·期 19
·195708
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IF 2.9
Xiaofang Zhang,Ke Wang,Zhenyu Li,Juanjuan Qi,Dongke Li,Jianqiang Luo,Jian Liu
Recently, the lead-free double perovskite Cs2AgBiBr6 has been considered as a promising candidate for next-generation nonvolatile memory and artificial synapse devices due to its high stability and low toxicity compared to its lead-based counterparts. In this work, we developed a simple and effective method to produce high-quality lead-free double perovskite Cs2AgBiBr6 thin films without pinholes and particles by applying a low-pressure assisted method under ambient condition with a relative humidity (RH) of about 45%. The formation of pinholes and Ag precipitation in the perovskite Cs2AgBiBr6 films is effectively suppressed by the proper ratio of N,N-dimenthylformamide (DMF) mixed in dimethyl sulfoxide (DMSO) solvents. Furthermore, the grain size of the Cs2AgBiBr6 films can be significantly increased by increasing the post-annealing temperature. Finally, a sandwiched structure memristor with an ITO/Cs2AgBiBr6/Ta configuration was successfully demonstrated, featuring ultralow operation voltage (VSet ∼ 57 ± 23 mV, VReset ∼ −692 ± 68 mV) and satisfactory memory window (the ratio of RHRS/RLRS ∼ 10 times), which makes it suitable for low-power consumption information storage devices.
研究领域:
材料科学
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电子器件
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
Materials Today Energy
·
2019
·
IF 0
Jingwei Xiu,Yangfan Shao,Linxun Chen,Yue Feng,Junfeng Dai,Xusheng Zhang,Yi Lin,Yudong Zhu,Zhenggang Wu,Yini Zheng,Hui Pan,Chang Liu,Xingqiang Shi,Xin Cheng,Zhubing He
Owning the merits of both lead-free and air-stable, the double-perovskite Cs 2 AgBiBr 6 has attracted increasing attention, but suffers low visible-light absorption coefficient due to its large indirect bandgap. Moreover, the electronic structure of its synthesized films has not been explored clearly yet. In this work, we developed a general and promising method to fabricate continuous, uniform and highly orientated Cs 2 AgBiBr 6 films in large scale on various substrates through capillary-assisted dip-coating method. Strikingly, those optimized films are single crystalline verified by φ-scan XRD . Its electronic structure was carefully studied independently by multi-photo-physical characterizations. Its bandgap can be tuned from 2.65 to 2.25 eV by changing the substrate temperature in growth from 40 to 160 °C. Essentially, their work-function (WF) was determined at −5.01 eV and WF-VBM is around 2 eV. This novel band structure with typical n-type characteristic, was further confirmed by DFT calculations, which reveals that the Cs interstitials and Br vacancies derived deep defect levels were fixed around its Fermi level, closer to the conduction band. This conclusion is different from its widely accepted p-type feature, but definitely deepens our understanding of this material and inspires us to find more valuable strategies of modulating its band structure and optoelectronic properties.
研究领域:
材料科学
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光电化学
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DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Chongguang Lyu,Chang Liu,Huihua Min,Xinyu Shi,Ran Jiang,Zhikang Ao,Xu Zhang,Chunli Wang,Huifang Ma,Lin Wang
Lead-free double perovskites have been an excellent candidate for resistive memories due to their mixed electronic-ionic properties, remarkable ambient stability and nontoxicity. However, the studies on resistive memories of rare-earth ion doping lead-free double perovskite are scarce to date. Here, we report the lead-free double perovskite Cs 2 AgBiBr 6 films with tuning rare earth Nd 3+ content by the vacuum sublimation and solution processing. The X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM) confirm that Nd-doped Cs 2 AgBiBr 6 films show high crystallinity and phase purity. We also systematically investigate the resistive memory properties of the resulted Cs 2 AgBiBr 6 films doped by different content Nd 3+ . The resistive memory devices demonstrate a typical write-once-read-many-times (WORM) behavior with low on-set voltage and long retention time. Particularly, the ON/OFF ratio of Nd-doped Cs 2 AgBiBr 6 film is 1000 times higher than that of the undoped Cs 2 AgBiBr 6 film. This study exhibits that Nd-doped Cs 2 AgBiBr 6 film provide a new material platform for lead-free perovskite-based application in future electronics and optoelectronics .
研究领域:
材料科学
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电子器件
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 23
·18758-18767
·
IF 2.779
Yang Akang,Zhang Lun,Xu Yinyan,Wang Qian,Lyu Mei,Lu Hongbo,Zhu Jun
Cs 2 AgBiBr 6 is a lead-free perovskite that shows great potential to solve the toxicity and instability of organic–inorganic lead perovskite. However, because of the poor interface contact and inferior film quality, the open-circuit voltage and the power conversion efficiency of the solar cells are inhibited. Herein, the Cs 2 AgBiBr 6 film quality is improved by adding formamidinium acetate into the precursor solution. With additive regulation, the grain size increases and the film surface is more smooth. The crystal structure remains unchanged, and the defect density decreases. Correspondingly, the average power conversion efficiency of the target device increases more than 30% than the control device. The best efficiency approaches 2.09%, and the open-circuit voltage is surprisingly high at 1.23 V, the highest value reported for Cs 2 AgBiBr 6 solar cells. Moreover, the device remains more than 90% of its initial efficiency after 40 days of storage under environmental conditions, showing excellent stability. This work is therefore helpful for enhancing the efficiency and stability of inorganic lead-free perovskite solar cells toward future commercialization.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 17
·5706-5712
·
IF 7.393
Jie Lao,Wen Xu,Chunli Jiang,Ni Zhong,Bobo Tian,Hechun Lin,Chunhua Luo,Jadranka Travas-sejdic,Hui Peng,Chun-Gang Duan
Halide perovskites (HPs) are promising materials for preparing nonvolatile memory and artificial synapse devices. However, the instability and toxicity of lead HPs seriously restrict their further application. Herein, a lead-free and air-stable Ag/polymethylmethacrylate (PMMA)/Cs2AgBiBr6/ITO device is fabricated, which exhibits typical resistive switching (RS) characteristics and synaptic behaviors, including long-term potentiation (LTP), long-term depression (LTD), paired-pulse facilitation (PPF) and spike-dependent plasticity. The ion migration of Br− and Ag+ in Cs2AgBiBr6 led to the formation and fracture of a conductive filament. Notably, no obvious decay in the device performance was observed after being directly exposed to the ambient environment for 20 days, indicating that the device exhibits good environmental stability. Furthermore, the recognition rate reaches 91.3% by using the MNIST handwritten data set. This air-stable and lead-free device provides a new candidate for the next generation of neuromorphic computation based on halide perovskites.
研究领域:
材料科学
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神经科学
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电子工程
✓ 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）