MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Jun Zheng,Linglin Wang,Lei Feng,Yuhan Gao,Feiyao Ren,Siyu Liu,Ting Zhou,Xiaochun Wu,Xin Lai,Daojiang Gao
Recently, Mn 4+ -activated fluoride red phosphors have received intensive attention due to their excellent luminescence properties. However, poor moisture resistance hinders their commercial application. Herein, (K 1- x Cs x ) 2 NbF 7 :Mn 4+ phosphors were designed and synthesized. All the obtained samples are rod-like microcrystals with monoclinic phase structure, Cs + -doping concentration has little influence on the microstructure while significantly impacts their luminescence properties. Specially, the composition optimized (K 1- x Cs x ) 2 NbF 7 :Mn 4+ ( x = 0.3) phosphor has the color purity of 94.20 %, the quantum yield of 53.90 % and the decay lifetime of 3.59 ms. More importantly, the optimized phosphor can maintain 83.20 % of the initial emission intensity after being immersed in distilled water for 1440 min, showing the excellent moisture resistance. A warm WLED with high CRI of 85 and low CCT of 4362 K is achieved by coating the obtained optimized red phosphor in chip. Our work demonstrates that the (K 1- x Cs x ) 2 NbF 7 :Mn 4+ red phosphors possess a great potential application in warm WLEDs.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Ruirui Zhang,Shugui Hua,Yuan Dang,Bing Zhang,Xiaoqin Sun,Sha Yu,Yingying He,Shuangli Chen,Yuanzhen Zhou
In this paper, the electrocatalytic performance of Ti/β-PbO 2 anode was improved by doping Cs into SnO 2 intermediate layer (Ti/Cs-SnO 2 /β-PbO 2 ) for the efficient degradation of fluoroquinolone wastewater. Compared with the conventional Ti/Sb-SnO 2 /β-PbO 2 anode, Cs-SnO 2 with the rougher surface increased the deposition amount and the thickness of β-PbO 2 active layer, thus forming the denser PbO 2 coating with smaller particle size and exposing more active sites. The partial replacement of Sn by Cs with the smaller ion radius induced the deformation of crystal lattice of SnO 2 , which further led the outer β-PbO 2 active layer grew along the advantageous (200) crystal plane and formed more point defects in the crystal lattice of β-PbO 2 . Thereby, the electron transfer rate at the anode interface was accelerated and the electrocatalytic performance of Ti/β-PbO 2 was significantly improved. To verify the practical application of the improved Ti/Cs-SnO 2 /β-PbO 2 electrode, levofloxacin (LFX) and ciprofloxacin (CIP) were selected as the typical target fluoroquinolones to evaluate the degradation efficiency of Ti/Cs-SnO 2 /β-PbO 2 anode. The removal rate exceeded more than 90% for the single and mixed fluoroquinolones wastewater. Moreover, after 5 times’ recycle, the degradation efficiency of LFX on Ti/Cs-SnO 2 /β-PbO 2 anode still remained over 90%. The potential mechanism of the enhanced electrocatalytic performance of Ti/Cs-SnO 2 /β-PbO 2 and the degradation pathways of fluoroquinolones were also inferred. It’s the first time to enhance the electrocatalytic performance of the Ti/β-PbO 2 anode by introducing monovalent alkali metal (C S ) into the SnO 2 intermediate layer and the proposed Ti/Cs-SnO 2 /β-PbO 2 anode would be a promising candidate to realize the efficient removal of the practical fluoroquinolones antibiotic wastewater.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 17
·6064
·
IF 3.4
Menghan Duan,Yunpeng Wang,Pingli Zhang,Luchao Du
Organic inorganic perovskite materials have received increasing attention in the optoelectronic field because of their unique properties. The ultrafast dynamics of photogenerated carriers determine photoelectric conversion efficiency, thus, it is feasible to influence the dynamics behavior of photogenerated carriers by regulating A-site cations. This paper mainly used transient absorption spectra (TAS) technology to study the photogenerated carriers relaxation processes of organic–inorganic perovskite CsxMA1−xPbI3materials at different x values. Three sets of time constants were obtained by global fitting at different values of x. The experimental results showed that the crystal structure of perovskite could be affected by adjusting the Cs+doping amount, thereby regulating the carrier dynamics. The appropriate amount of A-cation doping not only maintained the organic–inorganic perovskite crystal phase, but also prolonged the photogenerated carrier’s lifetime. The 10% Cs+doping CsxMA1−xPbI3perovskite has potential for solar cell applications. We hope that our research can provide dynamics support for the development of organic–inorganic perovskite in solar cells.Keywords:Cs+doping MAPbI3perovskite;transient absorption spectra;crystal structure;carriers dynamics
研究领域:
材料科学
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光电子学
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太阳能电池研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Shaowei Wang,Huijing Liu,Hari Bala,Beibei Zong,Liwen Huang,Zu-an Guo,Wuyou Fu,Bo Zhang,Guang Sun,Jianliang Cao,Zhanying Zhang
Hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrode were fabricated under a high humidity air environment and the performance of Cs + doping in methylammonium lead iodide perovskite (Cs x MA 1- x PbI 3 ) as light absorber layer was investigated and discussed. After the doping of Cs + , the excellent morphology, crystallinity and light absorption of perovskite thin films were observed by corresponding test methods, leading to the higher short-circuit current density and open-circuit voltage in the relevant devices. However, excessive Cs + doping can damage the performance of PSCs. The optimized device with x = 0.05, exhibited open-circuit voltage of 956 mV, short-circuit current density of 21.73 mA/cm 2 , fill factor of 0.509 and the power conversion efficiency ( PCE ) of 10.57% under AM 1.5G illumination showing a 16% enhancement than pure MAPbI 3 devices. The PSCs based on carbon counter electrode also showed high stability, despite being stored under ambient air without encapsulation. After 1000 h, the Cs 0.05 MA 0.95 PbI 3 devices maintained more than 90% of their initial PCE . The long-term stability can be attributed to the synergistic interaction of Cs + on the solid solution strengthening of MAPbI 3 and the protection of the hydrophobic carbon electrode on the perovskite active layer.
研究领域:
材料科学
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能源技术
·
光电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Zhimin Xu,Zhaobin Zhang,Xingfu Zhou
Vertical-oriented Cs-doped rutile TiO 2 nanorod (Cs-TiO 2 NR) arrays were prepared without a seed layer through the hydrothermal method . One-dimension TiO 2 nanorod (TiO 2 NR) arrays not only provide a direct and fast channel for charge transfer but also increase the perovskite loading amount. Further research shows that the conduction band minimum of Cs-TiO 2 NRs increases from − 3.94 eV to − 3.86 eV when compared with the pristine TiO 2 NRs, which favors the positive band alignment at the ETL/perovskite interface and reduces the carrier recombination and energy loss. Furthermore, we simultaneously replaced the expensive and unstable organic hole transport layer and noble metal electrode with a carbon electrode for the purpose of reducing the cost of the PSCs . The study proves that Cs-TiO 2 NRs not only improve the energy level arrangement at the ETL/perovskite interface but also reduce the density of defect states at the interface and increase carrier lifetime. The hole-transport-material-free carbon-based all-inorganic FTO/Cs-TiO 2 NRs/CsPbI 2.25 Br 0.75 /C solar devices exhibited a high-power conversion efficiency (PCE) of 12.72%, showing a 16% increase in PCE when compared with the control device. This work opens the door to the preparation of high-efficiency hole-transport-material-free carbon-based all-inorganic PSCs via the energy level calibration engineering.
研究领域:
材料科学
·
光伏技术
✓ 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）