ACS Applied Energy Materials
·
2022
·
IF 6.959
Huanxin Peng,Ping Fan,Zhuanghao Zheng,Shuo Chen,Guangxing Liang
Environmentally friendly lead-free Cs2AgBiBr6 double perovskites have emerged as potential materials for photovoltaic applications owing to their nontoxicity and high stability. However, the low solubility of precursors in the solution method and the deviated composition in the reported sequential evaporation process are still the challenges to obtain highly pure Cs2AgBiBr6 phase films. In this work, we proposed a single-source vapor deposition process for high-quality Cs2AgBiBr6 films with an effective thermally induced phase-controlled strategy. The microstructure, composition, and photoelectric properties of Cs2AgBiBr6 films with different heat treatments were investigated, and the phase evolution of Cs2AgBiBr6 film formation was figured out. High-phase purity, uniformity, smoothness of the surface, well-defined grain structure, and desired composition stoichiometry of Cs2AgBiBr6 films led to an optimized power conversion of 1.38% for a planar device structure with excellent stability. Our results demonstrate the feasibility of employing a single-source vapor deposition technique to fabricate high-quality double perovskite thin films, which paves the way for further development of various optoelectronic devices based on these promising lead-free semiconductors.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
纳米技术
✓ 已验证
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2023
·
IF 2.1
Zhigang Li,Yuanjie Sun,Hongtao Zhao
Lead free double perovskite nanocrystals is an ideal alternate considering its nontoxic and stable property comparing with their counterpart lead halide perovskite NCs. A simple solution synthesis strategy was used to prepare lead-free double perovskite Cs 2 AgBiBr 6 nanocrystals (NCs) doped with Na ions , resulting in NCs with a monodisperse state, homogeneous morphology, and good crystallinity . By adjusting the amount of Na + doping, the band gap of the NCs was significantly increased from 2.57 eV to 3.00 eV. Furthermore, the relatively low value of photoluminescence quantum yield (PLQY) in the original Cs 2 AgBiBr 6 NCs (∼0.5%) was increased to about 8.5% when doped with 60% Na + . Additionally, the exciton lifetime of the NCs was extended to 16.15 ns compared to the original 2 ns. As a result, the doping of Na + significantly enhanced the PLQY of Cs 2 AgBiBr 6 NCs, indicating their potential value for use in optoelectronic devices .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
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
·
神经科学
·
电子工程
✓ 已验证
产品关联
DOI
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
·
光电化学
✓ 已验证
DOI
Crystals
·
2021
·Vol. 11
·期 9
·1101
·
IF 2.589
Hui Chen,Cuncun Wu,Ri Li,Hongjian Chen
A three-dimensional cellular automata-lattice Boltzmann (CA-LBM) coupling model is established to simulate the facet growth process and the controlled cooling growth process of Cs2AgBiBr6perovskite single crystals. In this model, the LBM method is used to calculate the real-time solute field, the CA method is used to simulate the crystal growth process driven by supersaturation of solute, and the geometric parametergrelated to the adjacent grid is introduced to reduce the influence of grid anisotropy. The verification of the model is achieved by comparing the simulation results with the experimental results. The comparison results show that a smaller cooling rate is helpful for the growth of large-size single crystals, which verifies the rationality and correctness of the model.
研究领域:
材料科学
·
晶体生长动力学
✓ 已验证
DOI
高影响因子
ChemPlusChem
·
2021
·Vol. 86
·期 11
·1530-1536
·
IF 2.863
Caixiang Sun,Feifei Luo,Liuxia Ruan,Junwei Tong,Linwei Yan,Yadan Zheng,Xiaoli Han,Yanlin Zhang,Xianmin Zhang
Graphical Lead-free Cs 2 AgBiBr 6- x Cl x ( x =0, 0.2, 0.4, 0.6, 0.8, 1.0) perovskite films were synthesized and characterized. The ITO/Cs 2 AgBiBr 6- x Cl x /Al devices were fabricated to investigate the memristive behaviors. As the chloride content increases, the ON/OFF ratio of the device increases from 10 3 to 10 4 , the average V SET and the V RESET decrease from −0.40 V to −0.21 V and from 1.55 V to 1.34 V, respectively. Resistance states of devices can be maintained after 100 switching cycles and 10 4 s of reading. Mixed halide perovskites are promising memristive materials because of their excellent electronic-ionic properties. In this work, lead-free Cs 2 AgBiBr 6- x Cl x ( x =0, 0.2, 0.4, 0.6, 0.8, 1.0) double perovskite films were fabricated using a one-step solution spin-coating method in air. Moreover, the ITO/Cs 2 AgBiBr 6- x Cl x /Al sandwich-like devices are fabricated to investigate the memristive behaviors. The present memristors exhibit nonvolatile and bipolar resistive switching behaviors without electroforming process. Interestingly, as the chloride content increases, the ON/OFF ratio of the device increases from 10 3 to 10 4 , the average SET voltage and the RESET voltage decrease from −0.40 V to −0.21 V and from 1.55 V to 1.34 V, respectively. In addition, resistance states of devices can be maintained after 100 switching cycles and 10 4 s of reading. This study provides new possibility for the development of low-power and environmentally friendly memristors.
研究领域:
材料科学
·
电子学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 12
·1760
·
IF 4.034
Ping Fan,Huan-Xin Peng,Zhuang-Hao Zheng,Zi-Hang Chen,Shi-Jie Tan,Xing-Ye Chen,Yan-Di Luo,Zheng-Hua Su,Jing-Ting Luo,Guang-Xing Liang
Lead-free double perovskites have been considered as a potential environmentally friendly photovoltaic material for substituting the hybrid lead halide perovskites due to their high stability and nontoxicity. Here, lead-free double perovskite Cs2AgBiBr6films are initially fabricated by single-source evaporation deposition under high vacuum condition. X-ray diffraction and scanning electron microscopy characterization show that the high crystallinity, flat, and pinhole-free double perovskite Cs2AgBiBr6films were obtained after post-annealing at 300 °C for 15 min. By changing the annealing temperature, annealing time, and film thickness, perovskite Cs2AgBiBr6solar cells with planar heterojunction structure of FTO/TiO2/Cs2AgBiBr6/Spiro-OMeTAD/Ag achieve an encouraging power conversion efficiency of 0.70%. Our preliminary work opens a feasible approach for preparing high-quality double perovskite Cs2AgBiBr6films wielding considerable potential for photovoltaic application.Keywords:lead-free;perovskite solar cell;thin film;single-source vapor deposition
研究领域:
材料科学
·
可再生能源
·
太阳能电池技术
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Lan Ding,Fenghua Bai,Burenbayaer Borjigin,Yuning Li,Huiqin Li,Xiaojing Wang
Solar-energy-driven CO 2 conversion into valuable chemical fuels holds great renewable potential. However, most photocatalysts' weak CO 2 adsorption limits more artificial photosynthesis for further utilization. Herein, we present an in situ assembling approach to produce stable Cs 2 AgBiBr 6 /Ce-UiO-66-H composite, in which a tight contact interface between the two participated components was constructed. Benefiting from the photocatalytic properties and high adsorption capacity for CO 2 , the optimized 20Cs 2 AgBiBr 6 /Ce-UiO-66-H adsorption-photocatalyst exhibits outstanding performance for reductive CO 2 deoxygenation with considerable CO generation rate (309.01 μmol g −1 h −1 ) under simulated solar light irradiation with 300 W Xe lamp, which is about 2.1 and 2.7 times than that of pure Cs 2 AgBiBr 6 and Ce-UiO-66-H, respectively. The excellent catalytic conversion of CO 2 is ascribed to the effective solar harvest and quickly photo-excited carriers’ separation in such assembled architecture. Importantly, due to the in-situ synthesis, Cs 2 AgBiBr 6 QDs are intercalated in the Ce-UiO-66-H frameworks and it could lead to improved stability and induce abundant oxygen vacancies in Cs 2 AgBiBr 6 /Ce-UiO-66-H, which can maintain unchangeable CO 2 conversion rate under wet air with consecutive ten hours of the recycling test. In this work, the combining metal–organic frameworks and lead-free halide perovskite provide great potential for artificial photocatalytic CO 2 -to-CO conversion under a mild gas–solid reaction condition via utilizing solar energy.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Hantao Wang,Yu Zou,Haoqing Guo,Wenjin Yu,Xinyu Guo,Xiangdong Li,Zehao Zhang,Ganghong Liu,Shuang Yang,Zhenyu Tang,Bo Qu,Zhijian Chen,Lixin Xiao
To address the toxicity and stability issues of traditional lead halide perovskite solar cells (PSCs), the development of lead-free PSCs, such as Cs2AgBiBr6 solar cells, is of great significance. However, due to the low defect formation energy of Cs2AgBiBr6, a large number of vacancies, including A-site vacancies and X-site vacancies, form during the fabrication process of the Cs2AgBiBr6 film, which seriously damage the performance of the devices. The traditional phenylethylammonium (PEA) cation, mainly focusing on passivating A-site vacancies, is incapable of reducing X-site vacancies and so results in a limited performance improvement in Cs2AgBiBr6 solar cells. Herein, inspired by the capability of the Lewis base to coordinate with metal cations, a series of N-heterocyclic amines are introduced to serve as a dual-site passivator, reducing A-site and X-site vacancies at the same time. The highest power conversion efficiency of modified Cs2AgBiBr6 solar cells has been increased 36% from 1.10 to 1.50%. Further investigation reveals that the higher electron density of additives would lead to a stronger interaction with metal cations like Ag+ and Bi3+, thus reducing more X-site defects and improving carrier dynamics. Our work provides a strategy for passivating perovskite with various kinds of defects and reveals the connection between the coordination capability of additives and device performance enhancement, which could be instructive in improving the performance of lead-free PSCs.
研究领域:
材料科学
·
太阳能
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 20
·1900234
·
IF 15.621
Weinan Yuan,Guangda Niu,Yeming Xian,Haodi Wu,Huamin Wang,Hang Yin,Peng Liu,Wenzhe Li,Jiandong Fan
The double perovskite Cs 2 AgBiBr 6 single crystal holds great potential for detecting applications because of its low minimum detectable dose rate and toxic-free merit. Nevertheless, the disordered arrangement of Ag + /Bi 3+ usually gives rise to unexpected structural distortion and thereafter heavily influences the photoelectric properties of the Cs 2 AgBiBr 6 single crystal. Herein, phenylethylamine bromide is demonstrated to be capable of in situ regulation of the order–disorder phase transition in the Cs 2 AgBiBr 6 single crystal. The improved ordering extent of alternatively arranged [AgX 6 ] 5− and [BiX 6 ] 3− octahedra is theoretically and experimentally proven to decrease the defect density and suppress self-trapped exciton formation, and thereby tune the band gap and enhance the carrier mobility, which consequently promotes its application in an X-ray detector. The performance of a corresponding detector based on PEA-Cs 2 AgBiBr 6 single crystal displays superior performances, e.g., longer carrier drift distance, higher photoconductive gain, and faster current response (13 vs 3190 µs). Prominently, the as-fabricated PEA-Cs 2 AgBiBr 6 single-crystal X-ray detector has an extremely high sensitivity with a value of 288.8 µC Gy air −1 cm −2 under a bias of 50 V (22.7 V mm −1 ), which largely outperforms those of their counterparts with lower ordering structure.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 8
·4302-4309
·
IF 11.9
Menghan Yu,Nan Wang,Kuo Lin,Dongxue Song,Jie Chen,Teng Liang,Jianhui Sun,Kai Pan,Honggang Fu
Photocatalytic selective oxidation of benzyl alcohol into benzaldehyde at normal temperature and pressure is one of the important topics in the catalysis field. Here, a lead-free double perovskite Cs2AgBiBr6 nanocrystal/mesoporous black TiO2 composite was prepared by a vacuum-assisted method, and then it was applied for photocatalytic selective oxidation. The photocatalytic oxidation of benzyl alcohol to benzaldehyde was found to occur with 75% conversion and 99% selectivity with the Cs2AgBiBr6 nanocrystal/black TiO2 composite, which were better than those of single Cs2AgBiBr6 nanocrystals and black TiO2, respectively. This was due to the formation of a Z-type heterogeneous structure between Cs2AgBiBr6 nanocrystals and black TiO2, which effectively promoted the separation and transfer of electrons and holes, ultimately leading to excellent photocatalytic activity. During the whole catalytic process, carbon-centered radicals were the key intermediates for the dehydrogenation of benzyl alcohol. This work may provide some practical suggestions for the fabrication of benzyl alcohol selective oxidation photocatalysts.
研究领域:
催化
·
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-10
·
IF 11.878
Yang Bo,Pan Weicheng,Wu Haodi,Niu Guangda,Yuan Jun-Hui,Xue Kan-Hao,Yin Lixiao,Du Xinyuan,Miao Xiang-Shui,Yang Xiaoquan,Xie Qingguo,Tang Jiang
X-ray detectors are broadly utilized in medical imaging and product inspection. Halide perovskites recently demonstrate excellent performance for direct X-ray detection. However, ionic migration causes large noise and baseline drift, limiting the detection and imaging performance. Here we largely eliminate the ionic migration in cesium silver bismuth bromide (Cs 2 AgBiBr 6 ) polycrystalline wafers by introducing bismuth oxybromide (BiOBr) as heteroepitaxial passivation layers. Good lattice match between BiOBr and Cs 2 AgBiBr 6 enables complete defect passivation and suppressed ionic migration. The detector hence achieves outstanding balanced performance with a signal drifting one order of magnitude lower than all previous studies, low noise (1/ f noise free), a high sensitivity of 250 µC Gy air −1 cm –2 , and a spatial resolution of 4.9 lp mm −1 . The wafer area could be easily scaled up by the isostatic-pressing method, together with the heteroepitaxial passivation, strengthens the competitiveness of Cs 2 AgBiBr 6 -based X-ray detectors as next-generation X-ray imaging flat panels.
研究领域:
材料科学
·
物理学
·
放射学
·
医学成像
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）