检索结果-内蒙古大学图书馆

Spin-induced orbital frustration in a hexagonal optical lattice

Physical Review Research 2021年第3期3卷 033274-033274页

作者： Yongqiang Li Jianmin Yuan Xiaoji Zhou Xiaopeng Li Department of Physics National University of Defense Technology Changsha 410073 People's Republic of China Department of Physics Graduate School of China Academy of Engineering Physics Beijing 100193 People's Republic of China State Key Laboratory of Advanced Optical Communication System and Network Department of Electronics Peking University Beijing 100871 People's Republic of China State Key Laboratory of Surface Physics Institute of Nanoelectronics and Quantum Computing and Department of Physics Fudan University Shanghai 200438 People's Republic of China Shanghai Qi Zhi Institute AI Tower Xuhui District Shanghai 200232 People's Republic of China

Complex lattices provide a versatile ground for fascinating quantum many-body physics. Here, we propose an exotic mechanics for generating orbital frustration in hexagonal lattices. We study two-component (pseudospin-12) Bose gases in p-orbital bands of two-dimensional hexagonal lattices, and find that the system exhibits previously untouched orbital frustration as a result of the interplay of spin and orbital degrees of freedom, in contrast to normal Ising-type orbital ordering of spinless p-orbital band bosons in two-dimensional hexagonal lattices. Based on the classification by symmetry analysis, we find the interplay of orbital frustration and strong interaction leads to exotic Mott and superfluid phases with spin-orbital intertwined orders, in spite of the complete absence of spin-orbital interaction in the Hamiltonian. Our study implies many-body correlations in a multiorbital setting could induce rich spin-orbital intertwined physics in complex lattice structures.

关键词： Bose-Einstein condensates Cold gases in optical lattices Exotic phases of matter Quantum phase transitions Dynamical mean field theory

来源：评论

学校读者我要写书评

暂无评论

Debris flow impact on flexible barrier: effects of debrisbarrier stiffness and flow aspect ratio

引用

Journal of Mountain Science 2019年第7期16卷 1629-1645页

作者： SONG Dong-ri ZHOU Gordon G.D CHOI Clarence Edward ZHENG Yun Key Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina The HKUST Jockey Club Institute for Advanced Study Hong Kong SARChina

Conventionally,flexible barriers are rated based on their ability to resist a free-falling boulder with a particular input ***,there is still no well-accepted approach for evaluating performance of flexible barrier under debris flow *** this study,a large-nonlinear finite-element model was used to back-analyze centrifuge tests to discern the effects of impact material type,barrier stiffness,and flow aspect ratio(flow height to flow length)on the reaction force between the impacting medium and flexible *** show that,in contrast to flexible barriers for resisting rockfall,the normal impact force induced by the highly frictional and viscous debris is insensitive to barrier *** is because the elongated distributions of kinetic energy are mainly dissipated by the internal and boundary shearing,and only a small portion is forwarded to the ***,a new stiffness number is proposed to characterize the equivalent stiffness between a debris flow or a boulder,and a flexible *** the circumstance of an extremely elongated debris flow event,i.e.,low aspect ratio,the load on a barrier is dominated by the static component and thus not sensitive to the barrier stiffness.

关键词： Debris flow Flexible barrier Impact Stiffness Flow aspect ratio

来源：评论

学校读者我要写书评

暂无评论

First-Principles Analysis on the Role of Rare-Earth Doping in Affecting Nitrogen Adsorption and Diffusion at Fe surface towards Clarified Catalytic Diffusion

SSRN

引用

SSRN 2020年

作者： Dai, X.Z. Yang, X.R. Zhang, S.H. Li, D.Y. Yang, Yang Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials Ministry of Education Anhui University of Technology Maanshan243002 China Research Center of Modern Surface and Interface Engineering Anhui University of Technology Maanshan243002 China School of Materials Science and Engineering Anhui University of Technology Maanshan243002 China School of Materials Science and Engineering Harbin Institute of Technology Harbin150001 China Department of Chemical and Materials Engineering University of Alberta EdmontonABT6G 1H9 Canada

The adsorption and diffusion of nitrogen atom on the Fe surface and in Fe subsurface with and without substitution of La and Ce in the surface layer were studied based on first-principles calculations. Nitrogen atoms are predicted to be adsorbed at hollow and long bridge sites on Fe(100) and Fe(110), respectively. The nitrogen atoms on Fe surfaces respectively with doped La and Ce in subsurface layer show similar trends. However, the nitrogen atom preferentially occupies the hollow site on both Fe(100) and Fe(110) with La or Ce doped in the surface layer. La doping in the surface layer lowers the adsorption energies of both Fe(100) and Fe(110), indicating that La doping endows stronger adsorption ability. The effect of the La doping on the adsorption energies was explained based on the configurations after relaxation. In the subsurface region, the nitrogen atom prefers to occupy the octahedral site in Fe slabs with and without La and Ce doping, respectively. Furthermore, La and Ce doping in surface layer stabilizes the system of Fe slab with nitrogen atom as a foreign interstitial. The penetration process of the nitrogen atom into Fe(100) surface layers with and without La or Ce doping as a rate-determining step were calculated and compared. This study provides a fundamental insight into the catalytic diffusion mechanism for nitriding iron surface involving rare-earth surface doping. © 2020, The Authors. All rights reserved.

关键词： Rare earths

来源：评论

学校读者我要写书评

暂无评论

High-Performance Flexible All-Perovskite Tandem Solar Cells with Reduced VOC-Deficit in Wide-Bandgap Subcell

arXiv

引用

arXiv 2022年

作者： Lai, Huagui Luo, Jincheng Zwirner, Yannick Olthof, Selina Wieczorek, Alexander Ye, Fangyuan Jeangros, Quentin Yin, Xinxing Akhundova, Fatima Ma, Tianshu He, Rui Kothandaraman, Radha K. Chin, Xinyu Gilshtein, Evgeniia Müller, André Wang, Changlei Thiesbrummel, Jarla Siol, Sebastian Prieto, José Márquez Unold, Thomas Stolterfoht, Martin Chen, Cong Tiwari, Ayodhya N. Zhao, Dewei Fu, Fan Laboratory for Thin Films and Photovoltaics Empa - Swiss Federal Laboratories for Materials Science and Technology Duebendorf Switzerland College of Materials Science and Engineering Engineering Research Center of Alternative Energy Materials & Devices Ministry of Education Sichuan University Sichuan Chengdu610065 China Department of Chemistry University of Cologne Greinstrasse 4-6 Cologne50939 Germany Laboratory for Surface Science and Coating Technologies Empa Swiss FederalLaboratories for Materials Science and Technology Switzerland Soft Matter Physics and Optoelectronics University of Potsdam Potsdam Germany Photovoltaics and Thin Film Electronics Laboratory Institute of Electrical andMicroengineering École Polytechnique Fédérale de Lausanne Neuchâtel Switzerland Jaquet-Droz 1 Neuchâtel2002 Switzerland China-Australia Institute for Advanced Materials and Manufacturing Jiaxing University Zhejiang Jiaxing314001 China Department of Structure and Dynamics of Energy Materials Helmholtz-Zentrum-Berlin Berlin Germany School of Optoelectronic Science and Engineering Collaborative Innovation Center of Suzhou Nano Science and Technology Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province Key Lab of Modern Optical Technologies of Education Ministry of China Soochow University Suzhou215006 China Clarendon Laboratory University of Oxford Parks Road OxfordOX1 3PU United Kingdom Institut für Physik and IRIS Adlershof Humboldt-Universität zu Berlin Berlin12489 Germany

Among various types of perovskite-based tandem solar cells (TSCs), all-perovskite TSCs are of particular attractiveness for building- and vehicle-integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power-to-weight ratio. However, the efficiency of flexible all-perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide-bandgap (WBG) perovskite solar cells on the flexible substrates as well as the low open-circuit voltage (VOC) in the WBG perovskite subcell. Here, we report that the use of self-assembled monolayers as hole-selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, we employ a post-deposition treatment with 2-thiopheneethylammonium chloride to further suppress the bulk and interfacial recombination, boosting the VOC of the WBG top cell to 1.29 V. Based on this, we present the first proof-of-concept four-terminal all-perovskite flexible TSC with a PCE of 22.6%. When integrating into two-terminal flexible tandems, we achieved 23.8% flexible all-perovskite TSCs with a superior VOC of 2.1 V, which is on par with the VOC reported on the 28% all-perovskite tandems grown on the rigid substrate. © 2022, CC BY.

关键词： Perovskite

来源：评论

学校读者我要写书评

暂无评论

Kinetics Controlled Perovskite Crystallization for High Performance Solar Cells

引用

Angewandte Chemie 2024年第14期136卷

作者： Jinghao Ge Ran Chen Yabin Ma Yunfan Wang Yingjie Hu Lu Zhang Fengzhu Li Xiaokang Ma Sai-Wing Tsang Jiaxue You Alex K. Y. Jen Shengzhong Frank Liu Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy Technology International Joint Research Center of Shaanxi Province for Photoelectric Materials Science Institute for Advanced Energy Materials School of Materials Science and Engineering Shaanxi Normal University No. 620 West Chang'an Avenue Xi'an 710119 China These authors contributed equally. School of Materials Science and Engineering Xi'an University of Science and Technology No. 67 Xiaozhai East Road Xi'an Shaanxi 710054 PR China Department of Materials Science and Engineering Hong Kong Institute for Clean Energy City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR China State Key Laboratory of Solidification Processing Northwestern Polytechnical University No. 127 Laodong West Road Xi'an Shaanxi 710072 PR China Dalian National Laboratory for Clean Energy iChEM Dalian Institute of Chemical Physics Chinese Academy of Sciences No.457 Zhongshan Road Shahekou District Dalian 116023 China University of the Chinese Academy of Sciences No. 80 Zhongguancun East Road Beijing 100039 China

The power conversion efficiencies (PCEs) of perovskite solar cells have recently developed rapidly compared to crystalline silicon solar cells. To have an effective way to control the crystallization of perovskite thin films is the key for achieving good device performance. However, a paradox in perovskite crystallization is from the mismatch between nucleation and Oswald ripening. Usually, the large numbers of nucleation sites tend to weak Oswald ripening. Here, we proposed a new mechanism to promote the formation of nucleation sites by reducing surface energy from 44.9 mN/m to 36.1 mN/m, to spontaneously accelerate the later Oswald ripening process by improving the grain solubility through the elastic modulus regulation. The ripening rate is increased from 2.37 Åm ⋅ s −1 to 4.61 Åm ⋅ s −1 during annealing. Finally, the solar cells derived from the optimized films showed significantly improved PCE from 23.14 % to 25.32 %. The long-term stability tests show excellent thermal stability (the optimized device without encapsulation maintaining 82 % of its initial PCE after 800 h aging at 85 °C) and an improved light stability under illumination. This work provides a new method, the elastic modulus regulation, to enhance the ripening process.

关键词： Perovskite solar cells Oswald ripening crystallization kinetics nucleation surface energy

来源：评论

学校读者我要写书评

暂无评论

Efficient perovskite solar cells via surface passivation by a multifunctional small organic ionic compound

引用

Journal of Materials Chemistry A 2020年第17期8卷 8313-8322页

作者： Xin Wu Lu Zhang Zhuo Xu Selina Olthof Xiaodong Ren Yucheng Liu Dong Yang Fei Gao Shengzhong (Frank) Liu Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal University Xi'an 710119 China Department Chemie Universität zu Köln Luxemburgerstr. 116 Köln Germany Materials Science and Engineering Pennsylvania State University University Park Pennsylvania 16802 USA Dalian National Laboratory for Clean Energy iChEM Dalian Institute of Chemical Physics Chinese Academy of Sciences University of the Chinese Academy of Sciences Beijing 100039 China Dalian 116023 Liaoning China

surface passivation is a proven strategy for preparing high efficiency planar perovskite solar cells. Herein, we report an effective surface passivation strategy using the multifunctional small organic ionic compound 1-ethylpyridinium chloride (EPC) in combination with (FAPbI₃)_0.95(MAPbBr₃)_0.05. It is found that the nitrogen atom in the pyridine group forms chemical bonds with under-coordinated lead ions in the perovskite film whereby the defect density is significantly reduced. The organic groups, including ethyl and pyridine, furthermore provide higher hydrophobicity for improved moisture stability. Finally, the chlorine anions were also found to play an important role in the defect passivation while further improving the perovskite crystallinity. Detailed theoretical study confirms that the EPC is indeed a good passivation agent for multiple defects. As a result, the power conversion efficiency is increased from 19.52% to as high as 21.19% via the EPC passivation and the devices show reduced hysteresis and increased stability.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Electrocaloric effects in ferroelectrics and multiferroics from first principles

引用

Journal of Materiomics 2025年第6期11卷

作者： Zhijun Jiang Xueqing Wan Bin Xu Jorge Íñiguez-González Laurent Bellaiche Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Advanced Functional Materials and Mesoscopic Physics School of Physics Xi'an Jiaotong University Xi'an 710049 China State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 China Jiangsu Key Laboratory of Frontier Material Physics and Devices School of Physical Science and Technology Soochow University Suzhou 215006 Jiangsu China Luxembourg Institute of Science and Technology (LIST) Avenue des Hauts-Fourneaux 5 L-4362 Esch/Alzette Luxembourg Department of Physics and Materials Science University of Luxembourg 41 Rue du Brill L-4422 Belvaux Luxembourg Smart Ferroic Materials Center Physics Department and Institute for Nanoscience and Engineering University of Arkansas Fayetteville AR 72701 USA Department of Materials Science and Engineering Tel Aviv University Ramat Aviv Tel Aviv 6997801 Israel

The electrocaloric (EC) effect characterizes the change in temperature or entropy of a material under the application of an external electric field. Ferroelectric and multiferroic materials have attracted considerable interest due to their potential for efficient solid-state refrigeration in a broad range of applications. In this review, we present recent applications of first-principles-based effective Hamiltonian, second-principles method, and spin Heisenberg model to study the EC effect in ferroelectrics, relaxor ferroelectrics, and multiferroic materials. Specifically, these methods are used to investigate the EC effect in perovskite ferroelectrics Pb(Zr 0.4 Ti 0.6 )O 3 , (Ba 0.5 Sr 0.5 )TiO 3 , PbTiO 3 , BaTiO 3 and PbTiO 3 /SrTiO 3 superlattices, relaxor ferroelectrics Ba(Zr, Ti)O 3 and Pb(Mg, Nb)O 3 , as well as rare-earth-substituted BiFeO 3 , BiCoO 3 and BiFeO 3 multiferroics, and Nd-substituted BiFeO 3 antiferroelectric solid solutions. Large electrocaloric responses are predicted in some of these compounds. In addition, we review the phenomenological models that can be used to analyze and understand these EC effect results.

关键词： Electrocaloric effect Ferroelectrics Relaxor ferroelectrics Multiferroics Effective Hamiltonian

来源：评论

学校读者我要写书评

暂无评论

CO Intermediate-Assisted Dynamic Cu Sintering During Electrocatalytic CO2Reduction on Cu−N−C Catalysts

引用

Angewandte Chemie 2024年第23期136卷

作者： Yanyang Qin Wenshan Zhao Chenfeng Xia Dr. Li-Juan Yu Dr. Fei Song Dr. Jianrui Zhang Dr. Tiantian Wu Prof. Rui Cao Prof. Shujiang Ding Prof. Bao Yu Xia Prof. Yaqiong Su School of Chemistry Engineering Research Center of Energy Storage Materials and Devices of Ministry of Education National Innovation Platform (Center) for Industry-Education Integration of Energy Storage Technology Xi'an Jiaotong University 710049 Xi'an China These authors contributed equally. School of Chemistry and Chemical Engineering Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service Failure Hubei Engineering Research Center for Biomaterials and Medical Protective Materials Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology (HUST) 430074 Wuhan China Research School of Chemistry Australian National University 2601 Canberra ACT Australia Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of Sciences 201800 Shanghai China Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University 710119 Xi'an China

The electrochemical CO 2 reduction reaction (eCO 2 RR) to multicarbon products has been widely recognized for Cu-based catalysts. However, the structural changes in Cu-based catalysts during the eCO 2 RR pose challenges to achieving an in-depth understanding of the structure–activity relationship, thereby limiting catalyst development. Herein, we employ constant-potential density functional theory calculations to investigate the sintering process of Cu single atoms of Cu−N−C single-atom catalysts into clusters under eCO 2 RR conditions. Systematic constant-potential ab initio molecular dynamics simulations revealed that the leaching of Cu−(CO) x moieties and subsequent agglomeration into clusters can be facilitated by synergistic adsorption of H and eCO 2 RR intermediates (e.g., CO). Increasing the Cu 2+ concentration or the applied potential can efficiently suppress Cu sintering. Both microkinetic simulations and experimental results further confirm that sintered Cu clusters play a crucial role in generating C 2 products. These findings provide significant insights into the dynamic evolution of Cu-based catalysts and the origin of their activity toward C 2 products during the eCO 2 RR.

关键词： CO2 reduction reaction Electrocatalysts Molecular dynamics Dynamic sintering Catalyst stability

来源：评论

学校读者我要写书评

暂无评论

Organic Solar Cells: Intermolecular Interaction Control Enables Co-optimization of Efficiency, Deformability, Mechanical and Thermal Stability of Stretchable Organic Solar Cells (Small 21/2021)

引用

Small 2021年第21期17卷

作者： Qinglian Zhu Jingwei Xue Lu Zhang Jialun Wen Baojun Lin Hafiz Bilal Naveed Zhaozhao Bi Jingming Xin Heng Zhao Chao Zhao Ke Zhou Shengzhong (Frank) Liu Wei Ma State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an 710049 China Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal University Xi'an 710119 China

来源：评论

学校读者我要写书评

暂无评论

Machine-Learning Modeling for Ultra-Stable High-Efficiency Perovskite Solar Cells

引用

advanced Energy Materials 2022年第41期12卷

作者： Yingjie Hu Xiaobing Hu Lu Zhang Tao Zheng Jiaxue You Binxia Jia Yabin Ma Xinyi Du Lei Zhang Jincheng Wang Bo Che Tao Chen Shengzhong (Frank) Liu Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy Technology Institute for Advanced Energy Materials School of Materials Science and Engineering Shaanxi Normal University Xi'an 710119 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China School of Chemistry and Materials Science Nanjing University of Information Science & Technology Nanjing 210044 China National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Materials for Energy Conversion School of Chemistry and Materials Science University of Science and Technology of China Hefei 230026 China Dalian National Laboratory for Clean Energy iChEM Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China University of the Chinese Academy of Sciences Beijing 100039 China

Understanding the key factor driving the efficiency and stability of semiconductor devices is vital. To date, the key factor influencing the long-term stability of perovskite solar cells (PSCs) remains unknown because of the many influencing factors. In this work, through machine learning, the influences of five factors, including grain size, defect density, bandgap, fluorescence lifetime, and surface roughness, on the efficiency and stability of PSCs have been revealed. It is found that the bandgap has the greatest influence on the efficiency, and the surface roughness and grain size are most influential to the long-term stability. A mathematical model is given to predict efficiency based on fluorescence lifetime and bandgap. Guided by the model, four groups of experiments are conducted to confirm the machine-learning predictions and a PSC with 23.4% efficiency and excellent long-term stability is obtained, as manifested by retention of 97.6% of the initial efficiency after 3288 h aging in the ambient environment, the best stability under these conditions. This work shows that machine learning is an effective means to enrich semiconductor physical models.

关键词： high efficiency machine learning perovskite solar cells stability surface polarization

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：