Materials Research Express
·
2020
·Vol. 7
·期 1
·015522
·
IF 1.929
Tingyu Song,Lifeng Gao,Qi Wei,Limin Yu,Shiwei Wang,Mingyao Zhang,Lisha Zhao,Yanhua Cai
Organic-inorganic hybrid halide perovskites have attracted great interest for scientists and entrepreneurs due to their intrinsic properties and considerable business prospects in recent years. Perovskite single crystal can determine its properties well because of no grain boundaries for itself, so it is necessary to study the nucleation and growth process of perovskite crystals. In this work, CH3NH3PbI3−xClx single crystals with about 10 mm sized are prepared. It's found that chlorine can restrict the nucleation and slow crystallization during the perovskite grown process. Moreover, the number of perovskite crystals can be controlled by tuning the content of chlorine in the precursor solutions, because chlorine can restrict the perovskite crystal nucleation as an inhibitor.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL PAPERS
·
2021
·Vol. 75
·期 5
·1949-1958
·
IF 2.097
Zou Heng,Cao Qin-bo,Liu Dian-wen,Chen Xiu-min,Jiao Yong
Abstract Improving the collecting ability of a collector is a crucial issue in phosphate flotation. In this work, ricinoleic acid (RA) was used as a collector for fluorapatite (FA, Ca 5 (PO 4 ) 3 F) flotation. There is an OH group in the middle of the RA molecule, and thus, hydrogen bonds (H-bonds) can be formed between RA species. The role of the H-bond between RA molecules in FA flotation was revealed by experimental and theoretical calculation methods. The flotation results suggested that RA was more efficient than oleic acid for FA flotation at pH 9. The RA − anion was chemisorbed onto the negative FA surface, forming calcium ricinoleate (Ca(RA) 2 ) precipitates. The crystallization of Ca(RA) 2 on the FA surface was aided by the H-bonds between RA species. On the other hand, the results of quantum chemistry calculations showed that the H-bond in Ca(RA) 2 resulted in the close packing of RA − anions. Such a packing structure may occur on the FA surface, which favors the formation of Ca(RA) 2 on the surface and FA flotation. Moreover, Ca(RA) 2 was more stable than calcium dioleate in solution, also contributing to the better flotation efficiency of RA. These theoretical calculation results clarified the beneficial effect of the H-bond between RA species on FA flotation at the atomic level. Graphic abstract
研究领域:
矿物加工工程
·
物理化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 16
·5594-5599
·
IF 7.059
Hechun Lin,Xu Zhang,Lele Cai,Jie Lao,Ruijuan Qi,Chunhua Luo,Shiyou Chen,Hui Peng,Rong Huang,Chungang Duan
The optoelectronic application of fluorescent lead halide perovskite (LHP) nanocrystals is limited by their poor stability in humid atmosphere. However, we found that high-quality and high-stability fluorescent perovskites embedded in PbBrOH can be synthesized via the reaction of PbBr2 with MBr (M: Cs or CH3NH3+) triggered with imidazole derivatives in water. Imidazole can etch and hydrolyze the nonluminescent MPbBr3 to form high-quality fluorescent perovskites. After the perovskites are formed, a protective PbBrOH matrix grows rapidly on the surface of the perovskite nanocrystals and acts as a water-resistant layer. The embedded fluorescent perovskites can exhibit great stability even in water, heat and UV light with a PLQY of up to 30%. Density functional theory (DFT) calculations show that the enhanced stability results from the positive energy cost of the water molecule entering the lattice of PbBrOH, which is much higher than the negative value for water entering CsPbBr3; therefore, water is prevented by the PbBrOH surface from entering the embedded fluorescent perovskite. The PbBrOH surface layer has twofold beneficial effects: (i) preventing water from entering the perovskite nanocrystals, (ii) dispersing the perovskite nanocrystals in the matrix and preventing their aggregation so that highly luminescent composites can be formed. Our strategy opens a new avenue for the development of high-efficiency and high-stability fluorescent inorganic and organic perovskites.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Cell Reports Physical Science
·
2023
·
IF 8.9
Ying Cui,Jiawei Jiang,Wenbo Mi,Yin Xiao
Chiral perovskites have drawn much attention due to their abundant applications in electronic, magnetic, and spintronic technologies. Herein, we report fabrication of a five-layer chiral perovskite nanowire (n = 5) and its polarity preference regulation using chiral phenylethylamine or 2- butylamine as chiral ligands. We verify that the chiroptical response of the five-layer nanowire is governed by the localized surface chiral potential related to the ligand-induced helical distortion of [PbX 6 ] 4– octahedra on the top and bottom layers. Accordingly, an optical enantiomeric pair is created by varying the ligand’s type or concentration rather than inversion of the ligand’s absolute configuration. This phenomenon cannot be achieved in perovskite nanoplates. Circularly polarized luminescence ranges from 450 nm to 580 nm, and a highest luminescence dissymmetry factor of (2.67 ± 0.5) × 10 −2 is achieved. This approach unlocks high-n chiral perovskite nanostructures and provides an additional degree of freedom beyond configurational chirality in regulating polarity.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-7
·
IF 12.121
Zhou Chun,Zhong Yichi,Dong Hongxing,Zheng Weihao,Tan Jiqing,Jie Qi,Pan Anlian,Zhang Long,Xie Wei
Perovskites—compounds with the CaTiO 3 -type crystal structure—show outstanding performance in photovoltaics and multiparameter optical emitters due to their large oscillator strength, strong solar absorption, and excellent charge-transport properties. However, the ability to realize and control many-body quantum states in perovskites, which would extend their application from classical optoelectronic materials to ultrafast quantum operation, remains an open research topic. Here, we generate a cooperative quantum state of excitons in a quantum dot ensemble based on a lead halide perovskite, and we control the ultrafast radiation of excitonic quantum ensembles by introducing optical microcavites. The stimulated radiation of excitonic quantum ensemble in a superlattice microcavity is demonstrated to not be limited by the classical population-inversion condition, leading to a picosecond radiative duration time to dissipate all of the in-phase dipoles. Such a perovskite-assembly superlattice microcavity with a tunable radiation rate promises potential applications in ultrafast, photoelectric-compatible quantum processors.
研究领域:
材料科学
·
光学
·
量子物理
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Chao Fan,Yaheng Zhang,Shouqiang Huang,Xinyu Yang,Jun Wang,Zhichun Li,Songjian Zhao,Weilin Zheng,Guobiao Li
Metal halide perovskites are restricted by their stability and environmental detriment due to the participation of expensive and toxic reagents. We have selected a green dry mechanical grinding method to synthesize the perovskite materials, and with the introduction of Zn powder (CZ), most of the bulk CsPbBr 3 /Cs 4 PbBr 6 phases (pure C) are converted to Cs 2 ZnBr 4 , which separates the remaining CsPbBr 3 NCs to form heterostructures on the surface ZnO layer of Zn. The photoluminescence (PL) of the resultant CZ samples first increases and then decreases as the Zn dosage changes, and the PL intensity of the optimum sample with 10 mmol of Zn (CZ10) increases to about 8 times that of pure C. The largely enhanced PL of CZ10 is originated from the remaining CsPbBr 3 NCs promoted by the weakened charge transfer from CsPbBr 3 to Cs 2 ZnBr 4 and the metallic Zn due to the formation of a quasi-type I heterostructure of Cs 2 ZnBr 4 /ZnO. After the calcination treatment at 700 ℃ (CZ10-C700), 80% of PL is maintained, but the photostability of CZ10-C700 is greatly enhanced compared with that of CZ10, and 99.3% of PL is kept after 150 h illumination, which is attributed to the encapsulation protection of CsPbBr 3 /Cs 2 ZnBr 4 by the ZnO layer on Zn.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Kejia He,Qiang Song,Zhennan Yan,Na Zheng,Qiang Yao
Alkaline injection is an effective way to control the emission of high concentration SO 3 caused by the use of high-sulfur coal and selective catalytic reduction (SCR), but its performance is affected by the competitive absorption of SO 2 . A fixed-bed reactor was used to study the competitive absorption of SO 3 and SO 2 by Ca(OH) 2 . The dynamic absorption curves in different atmospheres were obtained, the intermediate products were characterized, and the competitive absorption mechanism was discussed. The absorption of SO 3 and SO 2 consists of the chemical kinetics-controlled and product layer diffusion-controlled stages. In the chemical kinetics-controlled stage, the SO 3 and SO 2 removal efficiencies were around 90% and 55% at first and then decreased; the SO 3 selectivity was around 0.1 at first and then increased. In the product layer diffusion-controlled stage, the SO 3 removal efficiency gradually decreased but kept greater than 10%, while the SO 2 removal efficiency deceased to zero; the SO 3 selectivity continued to increase and reached 0.31 at most when SO 2 absorption ceased. There existed significant competition between SO 3 and SO 2 absorption. The increasing SO 3 concentration promoted the SO 3 absorption and the increasing SO 2 concentration decreased it. The absorption of SO 3 increased the intensity of the SO 4 2 - band, decrease the intensity of the SO 3 2 - band, and made the product layer more compact. The possibility of SO 3 reacting with the components (CaSO 3 , CaSO 4 and CaCO 3 ) on the reacted Ca(OH) 2 surface was analyzed. Ionic diffusion was proposed as the main mechanism of the continuous SO 3 absorption after the formation of a dense product layer.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
iScience
·
2023
·Vol. 26
·期 4
·106461-106461
·
IF 5.8
Shuaibo Zhai,Jiaqi Gong,Yifei Feng,Zhongbao Que,Weiwei Mao,Xuemin He,Yannan Xie,Xing’ao Li,Liang Chu
Memristors are promising information storage devices for commercial applications because of their long endurance and low power consumption. Particularly, perovskite memristors have revealed excellent resistive switching (RS) properties owing to the fast ion migration and solution fabrication process. Here, an n-i-p type double perovskite memristor with "ITO/SnO 2 /Cs 2 AgBiBr 6 /NiO x /Ag" architecture was developed and demonstrated to reveal three resistance states because of the p-n junction electric field coupled with ion migration. The devices exhibited reliable filamentary with an on/off ratio exceeding 50. The RS characteristics remained unchanged after 1000 s read and 300 switching cycles. The synaptic functions were examined through long-term depression and potentiation measurements. Significantly, the device still worked after one year to reveal long-term stability because of the all-inorganic layers. This work indicates a novel idea for designing a multistate memristor by utilizing the p-n junction unidirectional conductivity during the forward and reverse scanning.
研究领域:
材料科学
·
电子工程
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Fuyi Zhou,Chang Yi,Jianhong Wu,You Ke,Yuyang Zhang,Nana Wang,Jianpu Wang
Mixing iodide and bromide in three-dimensional metal-halide perovskites is a facile strategy for achieving red light-emitting diodes (LEDs). However, these devices often face challenges such as instability in electroluminescence spectra and low brightness due to phase segregation in mixed-halide perovskites. Here, we demonstrate spectrally stable and bright red perovskite LEDs by substituting some of the halide ions with pseudohalogen thiocyanate ions (SCN–). We find that SCN– can occupy halogen vacancies, thereby releasing microstrain and passivating defects in the perovskite crystals. This leads to the suppression of mixed-halide phase segregation under electrical bias. As a result, the red perovskite LEDs exhibit a high brightness of >35 000 cd m–2 with stable Commission Internationale de l’Eclairage (CIE) coordinates of (0.713, 0.282). This brightness surpasses that of the best-performing red perovskite LEDs, showing great promise for advancing perovskite LEDs in display and lighting applications.
研究领域:
材料科学
·
光电子学
·
固体物理学
·
纳米技术
✓ 已验证
DOI
高影响因子
Advanced Materials Technologies
·
2022
·Vol. 8
·期 1
·2200679
·
IF 8.856
Tong Chen,Chunyun Wang,Guoshen Yang,Qiang Lou,Qingping Lin,Shengdong Zhang,Hang Zhou
Monolithic integration of perovskite materials and their optoelectronic devices with well-developed thin-film transistor (TFT) backplane is leading to new applications in displays and image sensors. Herein, a scalable polyimide assisted patterning approach for monolithic integration of perovskite based high-sensitive phototransistor array on indium gallium zinc oxide (IGZO) active matrix backplane is introduced. Polyimide vias are first formed by conventional photolithography process, through which uniform perovskite films of arbitrary patterns with feature size less than 20 µm are fabricated by spin-on-patterning method. Using this technique, patterns of quasi 2D perovskite photoabsorbing layer are precisely deposited onto the channel area of the photosensing IGZO TFT, forming high-performance phototransistors with responsivity and detectivity reaching 835.7 A W −1 and 5.4 × 10 12 Jones, respectively. An image sensor with 8 × 8 pixels array containing both photosensing perovskite/IGZO transistors and switching IGZO transistors is demonstrated, in which the switching IGZO transistor elements on the backplane are protected by the non-patterned region of the polyimide encapsulation layer. This whole fabrication process is compatible with TFT manufacturing process and will significantly reduce the cost needed for constructing next generation high-resolution image sensors.
研究领域:
材料科学
·
电子工程
·
光电子学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2020
·
IF 4.608
Bing Liu,Rongli Cui,Huan Huang,Xihong Guo,Shouwei Zuo,Jinquan Dong,Huanli Yao,Ying Li,Dangui Zhao,Jiahao Wang,Jing Zhang,Yu Chen,Junliang Yang,Baoyun Sun
The crystal structure of perovskite has a significant influence on the photovoltaic performance and stability of perovskite solar cells (PSCs). Pb 4+ is introduced into CH 3 NH 3 PbI 3 (MAPbI 3 )-based PSCs by participating the octahedral [PbI 6 ] 4- structure, then to induce the formation of stronger Pb-I bond and reduce [PbI 6 ] 4- octahedron distortion, which would improve structural symmetry, decrease the degree of disorder and be beneficial to the crystallization of perovskites . Synchrotron based X-ray absorption fine spectroscope (XAFS) revealed that the existence of higher valence state lead could be realized by doping Pb 4+ directly or induced by electron withdrawing group, in consequence the [PbI 6 ] 4- octahedral structure becomes more stable. Grazing incidence X-ray diffraction (GIXRD) especially demonstrates that Pb 4+ with appropriate proportion may well replace part of Pb 2+ to form an uniform phase in the primal perovskite structure to improve the crystallization on the surface and homogeneous out-of-plane (OOP) ordered crystal accumulation in the bulk, which is also important for improving the efficiency and stability of PSCs. As a result, a power conversion efficiency (PCE) exhibits a 42.1% increase with the doping of 0.03% PbF 4 and 0.075% PCBM compared with a pristine device and its stability improves markedly after 30 days of storage in ambient atmosphere.
研究领域:
材料科学
·
能源研究
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2020
·
IF 5.88
Tingyu Yang,Jilagamazhi Fu,Liang Ma,Hong Du,Xiaoqing Yue,Bosheng Zhao,Cuiyan Wang
In biomineralization, organisms have the abilities to produce biominerals with superior properties. One of the most attractive features of biominerals is the presence of the proteins consisting of different contents of amino acids in crystals. In the present work, L-phenylalanine (Phe) was used as an additive for the controllable crystallization of calcium carbonate (CaCO 3 ). The obtained CaCO 3 crystals were characterized by field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), elemental analysis and high-resolution transmission electron microscopy (HRTEM). The experimental results suggest that single calcite crystals are formed at low Phe concentrations. High concentrations of Phe inhibit the nucleation and growth of calcite, and promote the formation of vaterite crystals with solid or hollow structures. The morphology and crystal form of CaCO 3 are also significantly affected by the flow rate of CO 2 . After that, a possible mechanism (competition mechanism) action of Phe in the formation of CaCO 3 is proposed. Finally, the effects of temperature on the formation of vaterite were determined to explore the growth mechanism of hexagonal vaterite. The work of controlling the preparation of CaCO 3 crystals in the presence of Phe will help us to imitate and learn nature, and bring new insights into understanding bionics. Meanwhile, it provides a new method for the synthesis of CaCO 3 biomaterials with different crystal forms and morphologies.
研究领域:
材料科学
·
生物矿化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）