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Advancing Carriers Mobility in MnSb2Te4 Thermoelectrics via Tailored Textures and Vacancy Modification

Advanced Energy Materials 2025年第0期

作者： Xu, Xiao Mao, Dasha Liedke, Maciej Oskar Butterling, Maik Cui, Juan Wang, Jinghan Luo, Yiyuan Ge, Zhenhua Hirschmann, Eric Wagner, Andreas He, Jiaqing Nielsch, Kornelius He, Ran Institute for Metallic Materials Leibniz Institute for Solid State and Materials Research Dresden01069 Germany Department of Physics Southern University of Science and Technology Shenzhen518055 China Institute of Radiation Physics Helmholtz-Zentrum Dresden-Rossendorf Dresden01328 Germany Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing100088 China Faculty of Materials Science and Engineering Kunming University of Science and Technology Kunming650093 China

Enhancing carrier mobility plays a crucial role in significantly improving thermoelectric performance. However, due to the lack of a systematic strategy, achieving high mobility remains an elusive goal for most compounds. In this study, the hot-forging method is applied to polycrystalline MnSb₂Te₄, achieving a remarkable 300% improvement in carrier mobility. Through electron backscattering diffraction microstructural analysis, it is demonstrated how optimizing textures can accelerate carrier movement in MnSb₂Te₄ bulk materials. Moreover, theoretical calculations, combined with experimental positron annihilation spectroscopy, reveal that Te vacancies help counteract intrinsic cation defects, leading to a simultaneous increase in carrier mobility. As a result, the hot-forged MnSb₂Te₄ specimen, with a diameter of 15 mm, reaches a record-high maximum figure of merit (ZT) value of 1.3 at 773 K and an impressive average ZT of 0.7 between 323 and 773 K. The experimental output efficiency of 4.6%, observed at 773 K on the MnSb₂Te₄-based single-leg module, further confirms that the improved transport properties are due to the enhanced carrier mobility. This comprehensive study offers valuable insights into mobility enhancement in MnSb₂Te₄ and provides a promising direction for exploring similar improvements in other thermoelectric materials. © 2025 The Author(s). Advanced Energy Materials published by Wiley-VCH GmbH.

关键词： Positron annihilation

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Phonon vibrational and transport properties of SnSe/SnS superlattice at finite temperatures

arXiv

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arXiv 2025年

作者： Xue, Feng-Ning Li, Wei Li, Zi Lu, Yong College of Mathematics and Physics Beijing University of Chemical Technology Beijing100029 China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing100081 China School of Electronic Information Engineering Lanzhou Institute of Technology Lanzhou730050 China Institute of Applied Physics and Computational Mathematics National Key Laboratory of Computational Physics Beijing100088 China

The structural stability and phonon properties of SnSe/SnS superlattices at finite temperatures have been studied using machine learning force field molecular dynamics and the anharmonic phonon approach. The vertical SnSe/SnS superlattice undergoes a phase transition from the Pnma phase to a novel P4/nmm phase at finite temperatures, which is different from the high-temperature Cmcm phase of the SnSe and SnS systems. The stability of P4/nmm phase is determined by molecular dynamics trajectories and anharmonic phonon dispersion relations. The imaginary modes of TO modes at the q=M(1/2 , 1/2 , 0) point of the P4/nmm phase in harmonic approximation become rigid at elevated temperatures. An analysis of phonon power spectra upon temperature also confirms the dynamic stabilization. The P4/nmm phase has higher symmetry than the Pnma phase, and the phase transition between them is accompanied by competition between the Jahn-Teller effect and phonon anharmonicity. Unlike the anisotropic distribution of Sn-Se/S bonds in the Pnma phase, the P4/nmm phase forms chemical bonds with similar bond lengths both in-plane and interlayer, and their resonance effect can significantly enhance phonon scattering. The calculated phonon density of states and lifetime is strongly temperature dependent, demonstrating the heavy anharmonicity in the SnSe/SnS system. The P4/nmm phase has an extremely low lattice thermal conductivity, close to the experimental values of SnSe and SnS. Moreover, with the reduction of band gap and the enhancement of band degeneracy near the Fermi level, the P4/nmm phase exhibits superior electronic transport properties and significantly enhanced response to infrared and visible light. This makes it show great potential in thermoelectric and photovoltaic applications. © 2025, CC BY-NC-ND.

关键词： Jahn-Teller effect

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Htem: High-Throughput Toolkit for Elasticity Modeling

SSRN

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SSRN 2025年

作者： Yang, Zhen Xian, Jiawei Xu, Yuanji Lin, De-Ye Wang, Qingchun Gao, Xingyu Tian, Fuyang Song, Haifeng Institute for Applied Physics University of Science and Technology Beijing Beijing100083 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing100094 China CAEP Software Center for High Performance Numerical Simulation Institute of Applied Physics and Computational Mathematics Beijing100094 China

The elasticity under varying temperatures and pressures is particularly significant for understanding mechanical properties and structural phase transitions. Consequently, there is an increasing demand for tools capable of determining elasticity across wide temperature and pressure ranges, either numerically or analytically. We propose HTEM, a comprehensive toolkit that automates the workflow for input generation, elastic calculations, modeling, and visualization within an integrated framework. HTEM performs simulations with four computational modes, allowing users to balance accuracy and efficiency. It incorporates a semi-analytic model for robust, high-precision elastic modeling with finite data combinations, even using sparse elasticity at high temperatures. To validate the workflows of calculation and modeling, we perform HTEM to study the elasticity of Si across wide temperature and pressure ranges. Results show the high precision and high efficiency of HTEM. And modeling mitigates noise from constant pressure ensemble simulations. Furthermore, HTEM provides detailed visualizations of elasticity and its anisotropy as functions of temperature and pressure, providing comprehensive insights into how the intrinsic properties of materials evolve under varying conditions. © 2025, The Authors. All rights reserved.

关键词： Elasticity

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Influence of the two-temperature effect on ionization potential depression in hot dense plasma

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Physical Review E 2025年第3期111卷 035208-035208页

作者： Qingbo Luo Xin Liang Chengliang Lin Xinlian Zhang Jianpeng Liu Cheng Gao Yong Hou Jianmin Yuan College of Science National University of Defense Technology Changsha Hunan 410073 People's Republic of China Hunan Key Laboratory of Extreme Matter and Applications National University of Defense Technology Changsha Hunan 410073 People's Republic of China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing 100094 People's Republic of China Institute of Atomic and Molecular Physics Jilin University Changchun Jilin 130012 People's Republic of China

In hot dense plasma, the interaction between charged particles leads to the ionization potential depression (IPD), which further affects the physical properties of plasma, such as opacity and equation of state. The experiment of IPD of solid-density Al plasma has indicated that present theoretical models cannot give reasonable descriptions of the IPD in hot dense plasma. So, reasonable theoretical methods are needed to describe the effects of hot dense environments on IPD, and the process of generating hot dense plasmas through the interaction between ultrashort laser pulse and solid-density matter also needs to be carefully considered. In the manuscript, two kinds of temperatures for ions and electrons are considered when we compute the ionization potential depression in hot dense plasma. And, the influences of the hot dense environments are included in the electronic structure calculations by using the modified flexible atomic code (FAC), which has included the screening of free electrons and the correlation of ions by correlation functions obtained from the hyper-netted chain (HNC) approximation. A self-consistent-field method is used to calculate the electronic structures. Based on the calculations, the IPD is obtained through the two-step model. Considering the interaction of the femtosecond laser on the solid-density Al plasma of Ciricosta's experiment, we use the two-temperature model to calculate the IPD in nonlocal thermodynamic equilibrium, and the theoretical results are in good agreement with the experimental results. In addition, we also calculated the electron collision ionization cross section and compared it with the results from other models.

关键词： Ionization potential

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Complex scene fall detection method based on improved YOLOv5 24

Complex scene fall detection method based on improved YOLOv5

引用

13th International Conference on Computing and Pattern Recognition, ICCPR 2024

作者： Li, Yifan Liu, Pengyu Kong, Lili Deng, Yiyang Liu, Weilong Chen, Shanji Chen, Jiali Yuan, Bowen School of Information Science and Technology Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing University of Technology Beijing China Hebei Hongyi Environmental Protection Technology Co. Ltd Dingzhou Hebei China Beijing-Dublin International College at BJUT Beijing University of Technology Beijing China Information Technology Co. Ltd Dingzhou Hebei China College of Physics and Electronic Information Engineering Qinghai Minzu University Qinghai China

ISBN: (纸本)9798400717482

Aiming at the existing deep learning-based fall detection model in multiple complex scenes such as multi-person scenes, long-distance scenes, and occlusion scenes, there are problems such as leakage detection and false detection. In this paper, we take the falling person as the research object, construct a dataset containing multiple complex scenes such as multi-person scenes, long-distance scenes, and occlusion scenes, and propose a fall detection model based on improved YOLOv5. By improving the backbone network and neck network structure of the detection model, the problem of low accuracy of fall detection due to incomplete target deformation features and target detail features in complex scenes is solved. The proposed algorithm in this paper achieves an average accuracy of 92.78% for fall detection in complex scenes, and the detection speed reaches 36 frames/second. © 2024 Copyright held by the owner/author(s).

关键词： Fall detection

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Compact source for quadripartite deterministically entangled optical fields

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Fundamental Research 2025年第1期5卷 132-137页

作者： Yanhong Liu Yaoyao Zhou Liang Wu Jiliang Qin Zhihui Yan Xiaojun Jia Department of Physics Taiyuan Normal UniversityJinzhong 030619China Institute of Computational and Applied Physics Taiyuan Normal UniversityJinzhong 030619China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China College of Information Engineering Shanxi Vocational University of Engineering Science and TechnologyJinzhong 030619China

Since entangled multiple optical fields were identified as the building blocks of quantum networks,the quadripartite entangled optical fields have been produced by using four degenerate optical parametric amplifiers or two nondegenerate optical parametric amplifiers(NOPAs).However,realizing an efficient and compact source for multiple quantum users has remained an outstanding challenge,hindering their practical ***,we proposed a compact and feasible scheme to deterministically entangle four spatially separated optical fields,employing only a single ***,two-sided output NOPA-based optical fields were coupled on a beam splitter network to form the quadripartite entangled state,causing the deterministic generation of both the Greenberger–Horne–Zeilinger(GHZ)and the linear cluster states in this compact entanglement *** also obtained the optimal experimental parameters based on the simulation results,thereby providing a direct reference for experimental *** findings propose that the resultant GHZ and linear cluster states can be potentially applied in quantum-enhanced information science,specifically in quantum secret sharing,controlled quantum teleportation networks,and quantum-entangled atomic ensemble networks.

关键词： Quadripartite entanglement Single NOPA Compact source GHZ state Cluster state

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Contrasting magnetism in VPS3 and CrI3 monolayers with the common honeycomb S=3/2 spin lattice

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Physical Review B 2025年第13期111卷 134421-134421页

作者： Ke Yang Yueyue Ning Yaozhenghang Ma Yuxuan Zhou Hua Wu College of Science University of Shanghai for Science and Technology Shanghai 200093 China Laboratory for Computational Physical Sciences (MOE) State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 China Shanghai Qi Zhi Institute Shanghai 200232 China Hefei National Laboratory Hefei 230088 China

Two-dimensional (2D) magnetic materials are promising candidates for spintronics and quantum technologies. One extensively studied example is the ferromagnetic (FM) CrI3 monolayer with the honeycomb Cr3+ (t2g3, S = 3/2) spin lattice, while VPS3 has the same honeycomb S = 3/2 spin lattice (V2+, t2g3) but displays Néel antiferromagnetism. In this paper, we study the electronic structure and particularly the contrasting magnetism of VPS3 and CrI3 monolayers, using density functional calculations, magnetic exchange pictures, maximally localized Wannier function (MLWF) analysis, and parallel tempering Monte Carlo simulations. We find that VPS3 is a Mott-Hubbard insulator but CrI3 is a charge-transfer insulator, and therefore their magnetic exchange mechanisms are essentially different. The first-nearest-neighbor (1NN) direct d−d exchange dominates in VPS3, thus leading to a strong antiferromagnetic (AF) coupling. However, the formation of vanadium vacancies, associated with instability of the low-valence V2+ ions, suppresses the AF coupling and thus strongly reduces the Néel temperature (TN) in line with experimental observation. In contrast, our results reveal that the major 1NN d−p−d superexchanges in CrI3 via different channels give rise to competing FM and AF couplings, ultimately resulting in a weak FM coupling as observed experimentally. After revisiting several important superexchange channels reported in the literature, based on our MLWF and tight-binding analyses, we note that some antiphase contributions must be subtly and simultaneously considered, and thus we provide a deeper insight into the FM coupling of CrI3. Moreover, we identify and compare the major contributions to the magnetic anisotropy, i.e., a weak shape anisotropy in VPS3 and a relatively strong exchange anisotropy in CrI3. Our paper offers a comprehensive understanding of 2D magnetism using spin-orbital states and distinct exchange channels.

关键词： Honeycomb structures

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Phonon vibrational and transport properties of SnSe/SnS superlattice at finite temperatures

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Physical Review B 2025年第14期111卷 144314-144314页

作者： Feng-ning Xue Wei Li Zi Li Yong Lu College of Mathematics and Physics Beijing University of Chemical Technology Beijing 100029 People's Republic of China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 People's Republic of China School of Electronic Information Engineering Lanzhou Institute of Technology Lanzhou 730050 People's Republic of China Institute of Applied Physics and Computational Mathematics and National Key Laboratory of Computational Physics Beijing 100088 People's Republic of China

The structural stability and phonon properties of SnSe/SnS superlattices at finite temperatures have been studied using machine learning force field molecular dynamics and the anharmonic phonon approach. The vertical SnSe/SnS superlattice undergoes a phase transition from the Pnma phase to a P4/nmm phase at finite temperatures, which is different from the high-temperature Cmcm phase of the SnSe and SnS systems. The stability of P4/nmm phase is determined by molecular dynamics trajectories and anharmonic phonon dispersion relations. The TO modes at the q=Γ(0,0,0) and q=M(1/2,1/2,0) points in the P4/nmm phase exhibit imaginary frequencies in the harmonic approximation but stabilize at elevated temperatures. An analysis of phonon power spectra upon temperature also confirms the dynamic stabilization. The P4/nmm phase has higher symmetry than the Pnma phase, and the phase transition between them is accompanied by competition between the Jahn-Teller effect and phonon anharmonicity. Unlike the anisotropic distribution of Sn-Se/S bonds in the Pnma phase, the P4/nmm phase forms chemical bonds with similar bond lengths both in plane and interlayer, and their resonance effect can significantly enhance phonon scattering. The calculated phonon density of states and lifetime are strongly temperature dependent, demonstrating the heavy anharmonicity in the SnSe/SnS system. The P4/nmm phase has an extremely low lattice thermal conductivity, close to the experimental values of SnSe and SnS. Moreover, with the reduction of band gap and the enhancement of band degeneracy near the Fermi level, the P4/nmm phase exhibits superior electronic transport properties and significantly enhanced response to infrared and visible light. This makes it show great potential in thermoelectric and photovoltaic applications.

关键词： Bond length

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Extended calculations of energy levels, radiative properties, and lifetimes for phosphorus-like Se XX

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Atomic Data and Nuclear Data Tables 2025年

作者： Wang, Kai Bai, Xuan Chen, Chong Yang Yan, Jun Department of Physics and Anhui Key Laboratory of Optoelectric Materials Science and Technology Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Normal University Wuhu241000 China Shanghai EBIT Lab Key Laboratory of Nuclear Physics and Ion-Beam Application Institute of Modern Physics Department of Nuclear Science and Technology Fudan University Shanghai200433 China Institute of Applied Physics and Computational Mathematics Beijing100088 China

Highly accurate calculations are performed for the lowest 151 fine-structure levels arising from the 3s23p3, 3s3p4, 3s23p23d, 3s3p33d, 3p5 and 3s23p3d2 configurations in P-like Se XX using the multiconfiguration Dirac–Hartree–Fock and the relativistic configuration interaction methods. Complete and consistent atomic data, including excitation energies, wavelengths, E1, E2, M1, M2 line strengths, oscillator strengths, transition rates, and radiative lifetimes for these 151 levels, are provided. Our data set is compared with the NIST compiled values and other available results. The present data are accurate enough for identification and deblending of emission lines involving the n=3 levels and are also useful for modeling and diagnosing fusion plasmas. These data can be considered as a benchmark for other calculations. © 2025

关键词： Excitation energy

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Point defects in two-dimensional high-entropy transition metal dichalcogenides: The effect of local chemical environments

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Physical Review B 2025年第15期111卷 155444-155444页

作者： Wenjiang Gao Meiyang Yu Yuli Yan Cuihuan Geng Huabing Yin Institute for Computational Materials Science Joint Center for Theoretical Physics Henan Key Laboratory of High Efficiency Energy Conversion Science and Technology and Henan International Joint Laboratory of New Energy Materials and Devices School of Physics and Electronics Henan University Kaifeng 475004 China School of Chemical and Environmental Engineering Anyang Institute of Technology Anyang 455000 China

Recently, two-dimensional (2D) high-entropy transition metal dichalcogenides (TMDCs), which combine the characteristics of high-entropy and 2D materials, have been successfully synthesized in experiments and garnered considerable attention. However, research on point defects in 2D high-entropy TMDCs remains limited. Therefore, we focus on investigating the structure and formation energy of the common point defects of the 2D high-entropy (WMoNbTaV)S2 monolayer using first-principles calculations. By comparing the low-, medium-, and high-entropy TMDC materials, we found that among the point defects, the single sulfur vacancy (VS1) and S-M antisite defects (SM) with relatively small defect formation energies are most easily formed. From a single ordered structure to a multicomponent disordered structure, the distribution of defect formation energies broadens, especially for the five-component (WMoNbTaV)S2 monolayer. This is caused by the increase in the types of metallic elements, which leads to a greater complexity in the local chemical environments around the defects. Further examination of the effects of local chemical environments on vacancy formation energies revealed a correlation between the vacancy formation energies of multicomponent 2D TMDCs and those of their single-component counterparts. This study elucidates the influence of local chemical environments on the point defect properties of 2D high-entropy TMDCs, offering new insights and strategies for controlling defect generation in these systems.

关键词： II-VI semiconductors

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