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A hierarchical heterostructure of CdS QDs confined on 3D ZnIn_(2)S_(4) with boosted charge transfer for photocatalytic CO_(2) reduction

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Nano Research 2021年第1期14卷 81-90页

作者： Zezhou Zhu Xiaoxia Li Yunteng Qu Fangyao Zhou Zhiyuan Wang Wenyu Wang Changming Zhao Huijuan Wang Liqiang Li Yagang Yao Qun Zhang Yuen Wu School of Nano-Tech and Nano-Bionics Hefei National Laboratory for Physical Sciences at the MicroscaleCollaborative Innovation Center of Chemistry for Energy Materials(iChEM)School of Chemistry and Materials Scienceand National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale Synergetic Innovation Center of Quantum Information and Quantum PhysicsDepartment of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China Division of Advanced Nanomaterials Suzhou Institute of Nano-tech and Nano-bionicsChinese Academy of SciencesSuzhou 215123China Center for Micro and Nanoscale Research and Fabrication University of Science and Technology of ChinaHefei 230026China

Metal sulfide based materials as photocatalysts for energy conversion are essential to produce value-added chemical fuels,but their intrinsically slow carrier dynamics and low activity are yet to be resolved.Herein,we developed a unique heterogeneously nanostructured ZnIn_(2)S_(4)-CdS heterostructure that involves zero-dimensional(0D)CdS quantum dots uniformly confined on three-dimensional(3D)ZnIn_(2)S_(4)nanoflowers,which achieves an excellent catalytic performance of CO_(2) photoconversion under visible-light irradiation.The obtained hierarchical heterostructure can significantly enhance the light harvesting,shorten the migration distance of carriers,and obviously accelerate the transport of electrons.As evidenced by the ultrafast transient absorption spectroscopy,the formed interface can effectively facilitate charge separation and transport.This work opens up a new avenue to carefully design the elaborate heterostructures for achieving optimal charge separation efficiency by lowering interfacial kinetic barriers and energy losses at the interface.

关键词： photocatalysis CO_(2)reduction charge transfer hierarchical heterostructure

Raman scattering investigation of twisted WS_(2)/MoS_(2) heterostructures: interlayer mechanical coupling versus charge transfer

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Nano Research 2021年第7期14卷 2215-2223页

作者： Lishu Wu Chunxiao Cong Jingzhi Shang Weihuang Yang Yu Chen Jiadong Zhou Wei Ai Yanlong Wang Shun Feng Hongbo Zhang Zheng Liu Ting Yu Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore School of Information Science and Technology Fudan UniversityShanghai 200433China Shaanxi Institute of Flexible Electronics Northwestern Polytechnical UniversityXi’an 710129China Engineering Research Center of Smart Microsensors and Microsystems Ministry of EducationCollege of Electronics and InformationHangzhou Dianzi UniversityHangzhou 310018China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Key Laboratory of Chemical Lasers Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Twisted van der Waals homo-and hetero-structures have aroused great attentions due to their unique physical properties,providing a new platform to explore the novel two-dimensional(2D)condensed matter physics.The robust dependence of phonon vibrations and electronic band structures on the twist angle has been intensively observed in transition metal dichalcogenide(TMD)homo-structures.However,the effects of twist angle on the lattice vibrational properties in the TMD heterostructures have not caused enough attention.Here,we report the distinct evolutions of Raman scattering and the underlying interlayer interactions in the twisted WS_(2)/MoS_(2) heterostructures.The shifts and linewidths of E_(2g)(Γ)and A_(1g)(Γ)phonon modes are found to be twist angle dependent.In particular,analogous to that of the twisted TMD homostructures,the frequency separations between E_(2g)(Γ)and A_(1g)(Γ)modes of MoS_(2) and WS_(2) in the twisted heterostructures varying with twist angle correlate with the interlayer mechanical coupling,essentially originating from the spacing-related repulsion between sulfur atoms.Moreover,the opposite shift behaviors and broadening of A_(1g)(Γ)modes caused by charge transfer are also observed in the twisted heterostructures.The calculated interlayer distances and band alignment of twisted WS_(2)/MoS_(2) through density functional theory further evidence our interpretations on the roles of the interlayer mechanical coupling and charge transfer in variations of Raman features.Such understanding and controlling of interlayer interaction through the stacking orientation are significant for future optoelectronic device design based on the newly emerged 2D heterostructures.

关键词： van der Waals heterostructures interlayer coupling Raman scattering twist angle charge transfer

Effects of charge transfer Agents on the Holographic Parameters of a Photopolymer

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Chinese Physics Letters 2002年第7期19卷 947-949页

作者：姚华文黄明举等 ShanghaiInstituteofOpticalandFineMechanics ChineseAcademyofSciencesShanghai201800

The principle of charge transfer agents was investigated experimentally. There is a compensation effect between triethanolamine (TEA) and diphenyliodonium hexafluorophosphate (DPI) in the polymerization process of a photopolymer. The experimental results illustrate that TEA has a stronger effect in the initial stage of exposure, and DPI has a stronger effect during the propagation stage of the polymerization process. We explain the main contributions of DPI in the superadditive photopolymer kinetics that results in an obvious increase of sensitivity.

关键词： charge transfer

Experimental and theoretical analysis on the charge transfer band of Y_2O_3:Eu nanocrystals

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Journal of Rare Earths 2011年第11期29卷 1009-1012页

作者：吴凌远闻军覃延广尹民夏上达艾孜提艾力 Department of Physics University of Science and Technology of China Department of Physics Xinjiang Normal University

Nanocrystalline cubic Y2O3：Eu were prepared by combustion reaction.The crystal structure and morphology were analyzed by means of X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The luminescent properties of the powder were investigated.The charge transfer band position showed redshift from 241 to 251 nm,which was related to the change of the local surroundings of Eu3＋ ions in nanocrystalline Y2O3：Eu.The ground-state electronic structure and charge transfer transition of both the bulk and nanocrystalline cubic Y2O3：Eu crystals were calculated by the ab initio self-consistent relativistic DV-Xα（discrete variational Xα） method.A complete 35-ion cluster was selected to simulate the local coordination surroundings of Eu doped in Y2O3 bulk crystals while five additional incomplete clusters were also selected to simulate the local surroundings of Eu ions in nanocrystals.It could be found that the charge transfer energies of the nanocrystalline Y2O3：Eu were less than that of the bulk counterpart,which was consistent with the redshift phenomenon of the CT band in the excitation spectrum of the nanocrystalline Y2O3：Eu.

关键词： Y2O3：Eu combustion method redshift charge transfer ab initio calculation rare earths

Energy and charge transfer from Guest to Host in Doped Organic Electroluminescent Devices

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Chinese Physics Letters 2002年第9期19卷 1356-1358页

作者： Li Hong-Jian Peng Jing-Cui Xu Xue-Mei Qu Shu Luo Xiao-Hua Zhao Chu-Jun Department of Applied Physics Hu'nan University Changsha 410082 College of Physics Science and Technology Central South University Changsha 410083

The luminescence properties of doped organic electroluminescent devices are explained by means of a Hamiltonian model. The results show that there is a corresponding relation between the amount of transferred charge and the change of the energy originating from charge transfer, and the relation can be influenced by dopant concentration. As the amount of transferred charge increases, the total energy decreases and the luminescence intensity increases. Therefore, we deduce that the energy transfer from guest to host may be derived from the charge transfer. For a given organic electroluminescent device, the maximum value of the conductivity can be observed in a specific dopant concentration. The calculated results show that the greater the transferred charges, the higher the conductivities in doped organic electroluminescent devices. The results agree basically with experimental results.

关键词： charge transfer

Interfacial charge transfer in WS2 monolayer/CsPbBr3 microplate heterostructure

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Frontiers of physics 2018年第4期13卷 103-109页

作者： Zhen-Zhong Yan Zhao-Han Jiang Jun-Peng Lu Zhen-Hua Ni School of Physics and Key Laboratory of MEMS of the Ministry of Education Southeast University Nanjing 211189 China

Integration of heterogenous materials produces compelling physical phenomena and increased perfor- mance of optoelectronic devices. In this work, we integrate CsPbBr3 microplate with WS2 monolayer to investigate the interfacial carrier transfer mechanism in the heterojunction. The quenching of photo- luminescence （PL） emission from CsPbBr3 and WS2 after heterostructure formation indicates efficient charge transfer in the junction. Low-temperature PL spectra reveal that the decreasing PL of WS2 arises from the vanishing of biexcitons. Photodetection based on the WS2/CsPbBr3 heterostructure is demonstrated. The higher performance from the junction further certifies the occurrence of charge transfer in the heterojunction.

关键词： TMDs inorganic perovskite heterostructure charge transfer

Enhanced charge transfer, Transport and Photovoltaic Efficiency in All-Polymer Organic Solar Cells by Polymer Backbone Fluorinationt

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Chinese Journal of Chemistry 2018年第4期36卷 280-286页

作者： jianxia Sun Feng Jin Haibin Zhao Jianyu Yuan Wanli Ma Institute of Functional Nano & Soft Material (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Soochow Unversity 199 Ren'ai Road Suzhou Jiangsu 215123 China Shanghai Ultra-precision Optical Manufacturing Engineering ResearchCenter and Key Laboratory of M cro and Nano Photonic Structures(Minstry of Education) Department of Optical Science and EngineeringFudan University Shanghai 200433 China

We successfully designed and synthesized two BDT-BT-T （BDT=benzo[1,2-b：4,5-b＇]dithiophene, BT-T=4,7-dithien-2-yl-2,1,3-benzothia- diazole） based polymers as the electron donor for application in all-polymer solar cells （all-PSCs）. By adopting N2200 as the electron acceptor, we system- atically investigated the impact of fluorination on the charge transfer, transport, blend morphology and photovoltaic properties of the relevant alI-PSCs. A best power conversion efficiency （PCE） of 3.4% was obtained for fluorinated PT-BT2F/N2200 （BT2F=difluorobenzo[c][1,2,5]thiadiazole） alI-PSCs in com- parison with that of 2.7% in non-fluorinated PT-BT/N2200 （BT=benzothiad（azole） based device. Herein, all-polymers blends adopting either non-fluori- nated PT-BT or fluorinated PT-BT2F exhibit similar morphology features. In depth optical spectrum measurements demonstrate that molecular fluorina- tion can further enhance charge transfer between donor and acceptor polymer. Moreover, all-polymer blends exhibit improved hole mobilities and more balanced carriers transport when adopting fluorinated donor polymer PT-BT2F. Therefore, although the PCE is relatively low, our findings may become important in understanding how subtle changes in molecular structure impact relevant optoelectronic properties and further improve the performance of all-PSCSs.

关键词： all-polymer solar cells fluorination charge transfer carrier transport morphology

Theoretical Investigation into Electronic Structures and charge transfer Properties of π-Conjugated System with Different Combinations of Thiophene and Vinyl/Butadiene

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Chinese Journal of Chemistry 2012年第10期30卷 2501-2508页

作者：赵春梅李春荣马妍赵蔡斌王文亮 Key Laboratory for Macromoleeular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'anShaanxi 710062China College of Environmental Science and Engineering Chang'an UniversityXi'anShaanxi 710054China

A series of combinations of thiophene and vinyl/butadiene were investigated by ab initio and DFT methods to explore their electronic structures and charge transfer properties. The results show that increasing thiophene ring and vinyl number is a rational strategy to raise the HOMO energy levels and lower the LUMO energy levels. Mov- ing the vinyl from the periphery to the core has the slight effect on the HOMO and LUMO energy levels. Further- more, replacing the middle vinyl and end-capped vinyl of 3b （T5V4） with the butadiene can lower LUMO energy levels and then facilitate the electron injection. Above all, the close hole and electron reorganization energies （2h and λ-e） are observed from these compounds. However, the λes are smaller than their respective λhs in some com- pounds, which is relatively rare in organic materials. Especially, the promising ambipolar material 3c （T5B4） is recommended theoretically for possessing the equivalent minimum Ah （0.24 eV） and 2e （0.24 eV）. The absorption wavelengths exhibit red shifts with the increasing of the thiophene ring and the vinyl number under the same con- figuration, which correspond to the reverse order of AEH_L and Eg. The linear relationships are found between experimental lowest singlet excited energies （Eexp） with theoretical values AEH-L and Eg.

关键词： thiophene vinyl butadiene electronic structure charge transfer TDDFT

Folded or nonfolded fluorophores incorporating naphthalene:Their fluorescent quenching driven by charge transfer or co-aggregation in the aqueous-organic binary solvent

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Chinese Chemical Letters 2010年第2期21卷 221-224页

作者： Zhou, Qi Zhong Liu, Shi Yong Zhao, Shu Min Jiang, Huang Jiang Taizhou Univ Dept Chem Taizhou 317000 Peoples R China Zhejiang Univ Dept Chem Hangzhou 310027 Peoples R China

Folded or nonfolded fluorophores incorporating naphthalene were synthesized and characterized by steady state fluorescence technique.Paraquat as an excellent quenching reagent quenched the fluorescence of Nel6 or nDs(n = 1-4) driven by charge transfer.Under aggregation of nDs,α-CD did not quench the fluorescence of 1D.At lower concentration,the quenching tendency ofα-CD against nDs is 2D>3D>4D,while at higher concentration,the tendency is 2D<3D<4D.α-CD showed the selective recognition on its flu...

关键词： Fluorophore Fluorescent quenching charge transfer Co-aggregation Selective recognition