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Enhanced reversibility of the magnetoelastic transition in(Mn,Fe)2(P,Si)alloys via minimizing the transition-induced elastic strain energy

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Journal of Materials science & technology 2022年第8期103卷 165-176页

作者： Xuefei Miao Yong Gong Fengqi Zhang Yurong You Luana Caron Fengjiao Qian Wenhui Guo Yujing Zhang Yuanyuan Gong Feng Xu Niels van Dijk Ekkes Brück MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Fundamental Aspects of Materials and Energy Department of Radiation Science and TechnologyDelft University of TechnologyMekelweg 15DelftJB 2629Netherlands Department of Physics Bielefeld UniversityBielefeld 33501Germany Helmholtz-Zentrum Berlin für Materialien und Energie Berlin 12489Germany College of Physics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Magnetocaloric materials undergoing reversible phase transitions are highly desirable for magnetic refrigeration applications.(Mn,Fe)_(2)(P,Si)alloys exhibit a giant magnetocaloric effect accompanied by a magnetoelastic transition,while the noticeable irreversibility causes drastic degradation of the magnetocaloric properties during consecutive cooling *** the present work,we performed a comprehensive study on the magnetoelastic transition of the(Mn,Fe)_(2)(P,Si)alloys by high-resolution transmission electron microscopy,in situ field-and temperature-dependent neutron powder diffraction as well as density functional theory calculations(DFT).We found a generalized relationship between the thermal hysteresis and the transition-induced elastic strain energy for the(Mn,Fe)_(2)(P,Si)*** thermal hysteresis was greatly reduced from 11 to 1 K by a mere 4 at.%substitution of Fe by Mo in the Mn_(1.15)Fe_(0.80)P_(0.45)Si_(0.55)*** reduction is found to be due to a strong reduction in the transition-induced elastic strain *** significantly enhanced reversibility of the magnetoelastic transition leads to a remarkable improvement of the reversible magnetocaloric properties,compared to the parent *** on the DFT calculations and the neutron diffraction experiments,we also elucidated the underlying mechanism of the tunable transition temperature for the(Mn,Fe)_(2)(P,Si)family,which can essentially be attributed to the strong competition between the covalent bonding and the ferromagnetic exchange *** present work provides not only a new strategy to improve the reversibility of a first-order magnetic transition but also essential insight into the electron-spin-lattice coupling in giant magnetocaloric materials.

关键词： Magnetocaloric effect (Mn Fe)2(P Si) Hysteresis Neutron diffraction

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Thermodynamically induced crystal restructuring to make CsPbCl_(3) single crystal films for weak light detection

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Nano Research 2024年第11期17卷 9775-9783页

作者： Xiyan Pan Tai An Jie Sun Hua Dong Zhu Ma Guangxing Liang Yongbo Yuan Yang Li Wuqiang Wu Yong Ding Liming Ding Center for Excellence in Nanoscience (CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS) National Center for Nanoscience and Technology Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China School of Electronic Science and Engineering Xi’an Jiaotong University Xi’an 710049 China School of New Energy and Materials Southwest Petroleum University Chengdu 610500 China College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen 518060 China School of Physics and Electronics Central South University Changsha 410083 China School of Energy and Power Jiangsu University of Science and Technology Zhenjiang 212000 China School of Chemistry Sun Yat-sen University Guangzhou 510006 China Beijing Key Laboratory of Novel Thin-Film Solar Cells North China Electric Power University Beijing 102206 China

CsPbCl_(3) perovskite is considered a highly promising material for ultraviolet (UV) photodetectors due to its exceptional thermal stability and excellent short-wavelength light response. However, its high lattice energy and low polarizability result in extremely low solubility in conventional solvents, making the synthesis of CsPbCl_(3) single crystals a significant challenge. In this study, we propose a novel thermodynamically induced crystal restructuring (TICR) process that can transform microcrystalline films (MCFs) into single crystal films (SCFs) within a short period. This method, for the first time, has successfully achieved the synthesis of centimeter-sized CsPbCl_(3) SCFs and the mechanism has been explored in depth using in-situ techniques. Furthermore, we report the first instance of a CsPbCl_(3) SCF UV photodiode, which exhibits a record-breaking on/off ratio of 3.32 × 10^(7) and a detectivity of up to 1.15 × 10^(14) Jones under 0 V bias. It demonstrates excellent response even under weak light conditions of 10 nW·cm^(−2) and maintains outstanding stability with almost no performance degradation after 15 months. This study provides a novel approach for the synthesis of perovskite single crystals and holds significant potential for advancing the development of high-performance optoelectronic devices.

关键词： CsPbCl3 single crystal film crystal restructuring photodiode ultraviolet detector

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Modulating perovskite crystallization and band alignment using coplanar molecules for high-performance indoor photovoltaics

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Journal of Energy Chemistry 2024年第11期98卷 383-390页

作者： Qu Yang Shuhan Fan Haozhe Zhang Zhenhuang Su Xingyu Gao Hui Shen Mingkui Wang Xiu Gong College of Physics &Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025GuizhouChina State Key Laboratory of Public Big Data Guizhou UniversityGuiyang 550025GuizhouChina Shanghai Synchrotron Radiation Facility(SSRF) Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Wuhan National Laboratory for Optoelectronics School of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan 430074HubeiChina

The proper bandgap and exceptional photostability enable CsPbI_(3) as a potential candidate for indoor photovoltaics(IPVs),but indoor power conversion efficiency(PCE) is impeded by serious nonradiative recombination stemming from challenges in incomplete DMAPbI_(3) conversion and lattice structure ***,the coplanar symmetric structu re of hexyl sulfide(HS) is employed to functionalize the CsPbI_(3) layer for fabricating highly efficient *** hydrogen bond between HS and DMAI promotes the conversion of DMAPbI_(3) to CsPbI_(3),while the copianar symmetric structure enhances crystalline ***,surface sulfidation during HS-induced growth results in the in situ formation of PbS,spontaneously creating a CsPbI_(3) N-P homojunction to enhance band alignment and carrier *** a result,the CsPbI_(3)&HS devices achieve an impressive indoor PCE of 39.90%(P_(in):334.6 μW cm^(-2),P_(out):133.5 μW cm^(-2)) under LED@2968 K,1062 lux,and maintain over 90% initial PCE for 800 h at ^(3)0% air ambient humidity.

关键词： Perovskite indoor photovoltaics CsPbI_(3) Coplanar symmetric structure molecules Crystallization kinetics Hydrogen bond N-P homojunction

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A general and facile calcination method to synthesize single-site catalysts for highly efficient electrochemical CO_(2) reduction

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Nano Research 2024年第5期17卷 3895-3901页

作者： Rui Sui Bingyan Wang Yongsheng Wang Jiajing Pei Wei Zhu Wenxing Chen Chunhui Li Ailing Sun Zhongbin Zhuang Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China College of Chemistry and Green Catalysis Center Zhengzhou UniversityZhengzhou 450001China State Key Lab of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Energy&Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

The electrochemical CO_(2) reduction reaction(CO_(2)RR)has received widespread attention as a promising method for producing sustainable chemicals and mitigating the global ***,we demonstrate a general and facile synthetic route for the metal-nitrogen-carbon(M-N-C)type catalyst by simply calcinating metal acetate and urea with commercial carbon black,which have potential application in CO_(2)*** synthesized Ni-NC-600 catalyst has the structure of single Ni atom coordinated with one N atom and three C atoms(Ni-N_(1)C_(3)),which is suggested by X-ray absorption *** Ni-NC-600 catalyst exhibits high CO_(2)RR catalytic performance and a high CO Faraday efficiency above 98%in a wide potential range from-0.7 to-1.3 V(*** hydrogen electrode(RHE)),superior to most of the reported Ni-N-C *** work has developed a facile strategy to synthesize high performance CO_(2)RR catalyst.

关键词： nickel single atom catalyst CO_(2)reduction reaction CO production electrocatalyst

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Chiral N-triflylphosphoramide-catalyzed asymmetric hydroamination of unactivated alkenes: a hetero-ene reaction mechanism

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Organic Chemistry Frontiers 2022年第6期9卷 1649-1661页

作者： Na Wang Li-Wen Fan Jin Zhang Qiang-Shuai Gu Jin-Shun Lin Guo-Qiang Chen Xin-Yuan Liu Peiyuan Yu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518071China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Department of Chemistry and Shenzhen Grubbs Institute Guangdong Provincial Key Laboratory of CatalysisSouthern University of Science and TechnologyShenzhen 518055China Academy for Advanced Interdisciplinary Studies and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China

A highly enantioselective intramolecular hydroamination reaction catalyzed by chiralN-triflylphosphoramide (NTPA) that features an exceptionally broad substrate scope of isolated unactivated alkenes was recently reported by some of us. Herein we report a detailed density functional theory(DFT) study that unveil an uncommon hetero-ene reaction mechanism for this transformation. The reaction changes from a stepwise mechanism involving discrete tertiary carbocation formation to a concertedmechanism to avoid the generation of energetically unfavorable secondary carbocation species for distinctly substituted alkene substrates. The reactivity of this reaction is primarily affected by the substituentson the internal carbon of the alkene, with the carbocation-stabilizing ones promoting the reaction. Inaddition, the reaction is also influenced by the substituents on the terminal alkene carbons: those diminishing the innate alkene polarization of the starting alkenes retard the reaction by disfavoring the formation of related transition states featuring highly polarized alkene residues. The steric effect of all thesealkene substituents was found to be largely unimportant due to the unique arrangement of the heteroene reaction complex that keeps the reacting alkene away from the sterically congested core region ofthe catalyst pocket. The lower acidity of chiral phosphoric acids than that of chiral NTPAs renders the protonated precomplex along the hetero-ene reaction pathway greatly thermodynamically disfavored. Thisindirectly results in a greater relative distortion in the corresponding transition state, which in turn causesreaction retardation. Our results demonstrate the use of intramolecular pericyclic reactions as an alternative strategy for alkene activation by chiral Brønsted acid catalysis and provide insights into the furtherdevelopment of asymmetric hydrofunctionalization of unactivated alkenes.

关键词： mechanism substituent asymmetric

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Practically Enhanced Hyperentanglement Concentration for Polarization-Spatial Hyperentangled Bell States with Linear Optics and Common Single-Photon Detectors

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Physical Review Applied 2023年第3期19卷 034044-034044页

作者： Gui-Long Jiang Wen-Qiang Liu Hai-Rui Wei School of Mathematics and Physics University of Science and Technology Beijing Beijing 100083 China Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements (MOE) School of Physics Beijing Institute of Technology Beijing 100081 China

Hyperentanglement, defined as the simultaneous entanglement in several independent degrees of freedom (DOFs) of a quantum system, is a fascinating resource in quantum information processing with its outstanding merits. Here we propose heralded hyperentanglement concentration protocols (hyper-ECPs) to concentrate an unknown partially less polarization-spatial hyperentangled Bell state with available linear optics and common single-photon detectors. By introducing time-delay DOFs, the schemes are highly efficient in that the success of the scheme can be accurately heralded by the detection signatures, and postselection techniques or photon-number-resolving detectors, necessary for previous experiments, are not required. Additionally, our linear optical architectures allow certain states, where concentration fails, to be recyclable, and a trick makes the success probabilities of our schemes higher than those of previous linear optical hyper-ECPs.

关键词： Entanglement manipulation Optical quantum information processing optoelectronics Photonics Polarization of light Quantum protocols Optical sources & detectors Single-photon detectors

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Quantum phase transition and critical behavior between the gapless topological phases

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Physical Review A 2024年第6期109卷 062226-062226页

作者： Hao-Long Zhang Han-Ze Li Sheng Yang Xue-Jia Yu Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information Engineering Institute for Quantum Science and Technology Department of Physics School of Physics and Optoelectronics Institute for Advanced Study in Physics and School of Physics

The phase transition between gapped topological phases represents a class of unconventional criticality beyond the Landau paradigm. However, recent research has shifted attention to topological phases without a bulk gap, where the phase transitions between them are still elusive. In this work, based on large-scale density-matrix renormalization-group techniques, we investigate the critical behaviors of the extended quantum XXZ model obtained by the Kennedy-Tasaki transformation. Using fidelity susceptibility as a diagnostic, we obtain a complete phase diagram, which includes both topological nontrivial and trivial gapless phases. Furthermore, as the XXZ-type anisotropy parameter Δ varies, both the critical points hc and correlation length exponent ν remain the same as in the Δ=0 case, characterized by c=3/2 (Ising plus free boson) conformal field theory. Our results indicate that fidelity susceptibility can effectively detect and reveal a stable unconventional critical line between the topologically distinct gapless phases for general Δ. This work serves as a valuable reference for further research on phase transitions within the gapless topological phase of matter.

关键词： Continuous phase transition Quantum phase transitions Topological phases of matter Critical exponents Density matrix renormalization group

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Study of the photovoltaic properties of small-molecule-doped porphyrin polymers 11

Study of the photovoltaic properties of small-molecule-doped...

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11th Global Conference on Polymer and Composite Materials, PCM 2024

作者： Ban, Jianfeng Yang, Zilong Xu, Shaoxiong Pan, Lulu Wu, Dang School of Materials Science and Engineering Guangdong University of Petrochemical Technology Maoming525000 China Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen518060 China Guangzhou Occupational Disease Prevention Hospital Guangzhou510000 China

Doping is a widely used method in semiconductor materials to introduce specific compounds, which plays a crucial role in molecular assembly and functionalization. In this study, the doping of porphyrin small molecules into porphyrin polymers was successfully conducted at various ratios. The results reveal that the UV absorption spectra exhibit absorption peaks ranging from 400 nm to 650 nm. Furthermore, the doped combination demonstrates impressive air stability, as evidenced by the HOMO energy levels being below the critical threshold for conjugated polymers in air (-5.2 eV). This feature guarantees the material's stability under typical atmospheric conditions. Moreover, the calculated LUMO levels are approximately 0.49-0.53 eV higher than the acceptor PCBM, indicating the potential of the doped material to function as an efficient donor component in solar cells. The successful doping of porphyrin small molecules into porphyrin polymers not only expands the range of available materials but also provides promising prospects for applications in optoelectronic devices. The capability to adjust the doping ratio enables precise customization of the properties of the resulting materials, rendering them suitable for a wide range of technological advancements. Overall, this study demonstrates the potential of doped porphyrin polymers as efficient donors in solar cells, highlighting their significance in renewable energy research. © 2024 Institute of physics Publishing. All rights reserved.

关键词： Conjugated polymers

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On-chip topological nanophotonic devices

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Chip 2022年第4期1卷 1-21页

作者： Cui-Cui Lu Hong-Yi Yuan Hong-Yu Zhang Wen Zhao Nian-En Zhang Yan-Ji Zheng Sayed Elshahat Yong-Chun Liu Key Laboratory of Advanced Optoelectronic Quantum Architecture and Mea-surements of Ministry of Education Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of TechnologyBeijing 100081China State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsFrontier Science Center for Quantum InformationTsinghua UniversityBeijing 100084China

On-chip topological nanophotonic devices,which take photons as in-formation carriers with topological protection during light propaga-tion,have great application potential in the next generation photonic *** topological photonic states enable the nanophotonic de-vices to be robust and stable,immune to scattering even with imper-fect *** development,opportunities and challenges of the on-chip topological nanophotonic devices have attracted great atten-tion of scholars,and desired to be *** this review,topologi-cal devices were introduced in the order of functionalities on an in-tegrated photonic chip,*** light source,topological light waveguiding,topological light division and selection,topological light manipulation and topological light ***,we gave out-looks for predicting and promoting the performances of on-chip topo-logical nanophotonic devices from the angles of non-Hermitian sys-tems,non-Abelian topology,metasurfaces,intelligent algorithms and multiple functional topological nanophotonic *** review provides rich knowledge about on-chip topological nanophotonic *** insights in this paper will spark inspiration and inspire new thinking for the realization of topological photonic chips.

关键词： Topological photonics Nanophotonic devices Photonic chip

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Sea-urchin-like ReS_(2) nanosheets with charge edge-collection effect as a novel cocatalyst for high-efficiency photocatalytic H_(2) evolution

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Chinese Chemical Letters 2022年第2期33卷 943-947页

作者： Bo Lin Bowen Ma Jiangang Chen Yao Zhou Jiadong Zhou Xiaoqing Yan Chao Xue Xiao Luo Qing Liu Jinyong Wang Renji Bian Guidong Yang Fucai Liu School of Optoelectronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China School of Physical and Mathematical Sciences Nanyang Technological UniversitySingapore 637371Singapore Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement(Ministry of Education) Beijing Key Lab of Nanophotonics&Ultraﬁne Optoelectronic Systemsand School of PhysicsBeijing Institute of TechnologyBeijing 100081China XJTU-Oxford International Joint Laboratory for Catalysis School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China State Centre for International Cooperation on Designer Low-carbon and Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China

The recombination of charge carriers arriving from the random charge movement in semiconductor pho-tocatalysts greatly limits the practical application of solar-driven H_(2)*** design of photo-catalytic systems with spatially oriented charge-transfer is a promising route to achieve high charge-separation efficiency for ***,novel sea-urchin-like Re S_(2)nanosheet/TiO_(2)nanoparticle heterojunctions(SURTHs)are *** unique sea-urchin-like structure endows the ReS_(2)cocat-alyst with an unusual charge edge-collection effect,which leads to a significant acceleration of charge separation and transfer,as evidenced by the well-designed selective photodeposition of Pt quantum dots in *** markedly improved charge transfer capacity contributes to a high photocatalytic H_(2)evo-lution rate of 3.71 mmol h^(−1)g^(−1)for SURTHs(an apparent quantum efficiency(AQE)of 16.09%),up to 231.9 times by contrast with that of P25 TiO_(2).This work would provide a new platform for designing the high-efficiency cocatalyst/photocatalyst system with excellent charge transfer capacity.

关键词： Sea-urchin-like ReS_(2)nanosheets Charge edge-collection effect 2D planar edges/tips Charge transfer Photocatalytic H_(2)evolution

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