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Mechanism investigation of A-site doping on modulating electronic band structure and photocatalytic performance towards CO_(2) reduction of LaFeO_(3) perovskite

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Nano Research 2024年第5期17卷 3733-3744页

作者： Chi Cao Jinshuo Li Yang Hu Lin Zhang Wensheng Yang State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China

Three kinds of metal atoms with different valence electronic configurations,Bi(6s^(2)6p^(3)),Y(4d^(1)5s^(2)),and Ce(4f^(1)5d^(1)6s^(2)),were selected to investigate the effect of A-site(La^(3+))doping on electronic band structure,photoelectric properties,and photocatalytic performance of LaFeO_(3) *** was identified that the Bi doped LaFeO_(3) presented significantly improved photocatalytic activity towards the reduction of CO_(2),while the Y or Ce doped LaFeO_(3) displayed decreased photocatalytic activity compared to the pristine LaFeO_(3).It was revealed that doping of all the three metal atoms resulted in narrowed band gap and thus extended light absorption of LaFeO_(3) by lowering its conduction band minimum(CBM).The recombination rate and mobility of the charge carriers were represented by the relative effective mass(D)between holes and electrons for pristine and A-site doped LaFeO_(3).The doping of Bi resulted in increased D value,attributed to the Bi 6s electron states at the valence band maximum(VBM),and thus promoted separation and transfer of the charge carriers and improved photocatalytic activity of LaFeO_(3).In contrast,the doping of Ce resulted in significantly decreased D value,induced by the highly localized Ce 4f hole states at the CBM,and thus higher recombination rate of the charge carriers and decreased photocatalytic activity of LaFeO_(3).Furthermore,the Y doped LaFeO_(3) with a slightly decreased D value presented slightly increased recombination rate of the charge carriers and thus decreased photocatalytic *** a work provides new insights into the A-site doping in LaFeO_(3) perovskite,which should be helpful for optimizing the electronic band structure and activity of perovskite-type photocatalysts at atomic level.

关键词： A-site doping electronic band structure charge carrier behavior photocatalytic CO_(2)reduction perovskite-type photocatalytsts

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electronic band structure from first-principles Green’s function approach:theory and implementations

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中国化学前沿:英文版 2011年第4期6卷 253-268页

作者： Hong JIANG Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Material Chemistry and ApplicationInstitute of Theoretical and Computational ChemistryCollege of ChemistryPeking University100871BeijingChina

electronic band structure is one of the most important intrinsic properties of a material,and is in particular crucial in electronic,photo-electronic and photo-catalytic ***-Sham Density-functional theory(KS-DFT)within currently available local or semi-local approximations to the exchange-correlation energy functional is problematic for the description of electronic band ***-body perturbation theory based on Green’s function(GF)provides a rigorous framework to describe excited-state properties of *** central ingredient of the GF-based many-body perturbation theory is the exchangecorrelation self-energy,which accounts for all nonclassical electron-electron interaction effects beyond the Hartree theory,and formally can be obtained by solving a set of complicated integro-differential equations,named Hedin’s *** GW approximation,in which the self-energy is simply a product of Green’s function and the screened Coulomb interaction(W),is currently the most accurate first-principles approach to describe electronic band structure properties of extended *** to KS-DFT,the computational efforts required for GW calculations are much *** numerical techniques or approximations have been developed to apply GW for realistic *** this paper,we give an overview of the theory of first-principles Green’s function approach in the GW approximation and review the state of the art for the implementation of GW in different representations and with different treatment of the frequency *** is hoped that further methodological developments will be inspired by this work so that the approach can be applied to more complicated and scientifically more interesting systems.

关键词： electronic band structure many-body perturbation theory GW approximation

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electronic band structure and Heat Capacity Calculation of Some TlX (X = Sb, Bi) Compounds

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Advances in Materials Physics and Chemistry 2016年第3期6卷 47-53页

作者： Neetu Paliwal Vipul Srivastava Ajeet Kumar Srivastava Department of Physics AISECT University Bhopal India Department of Engineering Physics NRI Institute of Research & Technology Bhopal India Department of Physics Dr. CV Raman University Bilaspur India

The tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA) has been used to calculate structural and electronic properties of thallium pnictides TlX (X = Sb, Bi). As a function of volume, the total energy is evaluated. Apart from this, equilibrium lattice parameter, bulk modulus, first order derivative, electronic and lattice heat co-efficient, Debye temperature and Grüneisen constants, band structure and density of states are calculated. From energy band diagram, we observed metallic behaviour in TlSb and TlBi compounds. The equilibrium lattice constants agreed well with the available data.

关键词： Thallium Pnictides TB-LMTO electronic band structure Heat Capacities Debye Temperature

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Comparison of electronic band structure and Electrical Transport Properties between Ge2Sb2Te5 and Ge1Sb2Te4 Phase-Change Materials

Comparison of Electronic Band Structure and Electrical Trans...

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第18届国际真空大会

作者： Ling Xu Fei Yang Yuanbao Liao Wenqiang Liu Dong Liu Jun Xu Zhongyuan Ma and Kunji Chen National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and electronic Materials Sciences and Technology School of Physics and School of electronic Science and Technology Nanjing University Nanjing 210093 People’s Republic of China

Ternary alloy, Ge2Sb2Te5, Ge1Sb2Te4 are two kinds of compounds along the GeTe-Sb2Te3 pseudobinary line. They are found to have good optical and electrical contrast between the amorphous and crystalline states and, and have featuring characteristics for phase change memory. In this study, the sputtering method is used to prepare Ge2Sb2Te5 and Ge1Sb2Te4 thin films. The band gaps of GST thin films are determined from the measured absorption spectra. With the help of Tauc equation,the estimated optical band gaps of the amorphous, fcc and hexagonal Ge2Sb2Te5 thin films are 0.8, 0.7 and 0.65 eV, respectively. The estimated band gaps of the amorphous, fcc and hexagonal Ge1Sb2Te4 thin films are 0.5 eV, 0.4 and 0.3 eV, which are smaller than that of amorphous. The results of the temperature dependence of the sheet resistance upon a heating rate show that both Ge2Sb2Te5 and Ge1Sb2Te4 thin film exhibit a temperature-activated electrical conductivity. We also measure the carrier mobility μ using surface acoustic wave technology, which is an appropriate method for materials with low conductivities. Typical mobilities for Ge2Sb2Te5 and Ge1Sb2Te4 thin films of about 0.001-1 cm2/Vs and 1-10 cm2/Vs in the temperature range of 300-480 K were found at amorphous and crystalline states respectively. Transport via the hopping among localized states （both from band tail of the valence band and structural vacancies such as localized Tellurium lone pairs） were thought to dominate the temperature between 20-80 C.

关键词： Ge2Sb2Te5 and Ge1Sb2Te4 phase-change materials electronic band structure Electrical transport properties

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Ternary layered boride MoAlB:A novel thermo-regulation microwave absorbing ceramic material

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Journal of Advanced Ceramics 2024年第5期13卷 699-710页

作者： Zhangjue Wang Fan Zhang Nannan Wang Wei Li Yongqiang Chen Hailong Wang Rui Zhang Yanqiu Zhu Bingbing Fan School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Academy of Sciences Zhengzhou 450046China State Key Laboratory of Featured Metal Materials and Life Cycle Safety for Composite structures MOE Key Laboratory of New Processing Technology for Nonferrous Metals MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China Department of Materials and Earth Sciences Technical University of DarmstadtDarmstadt 64287Germany School of Material Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China Department of Engineering Faculty of EnvironmentScience and EconomyUniversity of ExeterExeter EX44QFUK

In the context of the fifth-generation(5G)smart era,the demand for electromagnetic wave(EMW)-absorbing materials has become increasingly prominent,so it is necessary to explore promising candidate *** work focuses on the exploration of the material absorbing properties of a MoAlB MAB(MAB represents a promising group of alternatives,where M stands for a transition metal,A typically denotes Al,and B is boron)phase ***,the first-principles calculations were performed to reveal the unique crystal and layered structure of the MoAlB ceramics and to predict their potential for use as an EMW absorption ***,a series of MoAlB ceramics were synthesized at temperatures ranging from 800 to 1300℃,and the influence of temperature on the phase compositions and microstructures of the obtained MoAlB ceramics was characterized and ***,the practical EMW absorption performance of the prepared MoAlB ceramics was evaluated via a combination of experiments and radar cross-sectional *** MoAlB sample synthesized at 900℃ exhibits superior EMW absorption performance,achieving an impressive minimum reflection loss(RL)of−50.33 *** unique layered structure and good electrical conductivity of the MoAlB samples are the main reasons for their enhanced wave absorption performance,which provides interfacial polarization and multiple dielectric loss ***,this study not only contributes to the understanding of the preparation of MoAlB materials but also provides potential guidance for their utilization in the realm of electromagnetic wave absorption.

关键词： MoAlB electronic band structure electromagnetic wave(EMW)absorption layered ternary boride density of states

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量子约束效应调制的二维层状MoSSe薄膜激子和电子能带结构及其光探测潜力（英文）

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Science China Materials 2024年第10期67卷 3087-3095页

作者：丁依凡朱绪丹唐红雨刘未名申淑雯樊嘉杰罗毅郑玉祥丛春晓罗思源张荣君 Department of Optical Science and Engineering Key Laboratory of Micro and Nano Photonic Structures (MOE) Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing Fudan University Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Proception Institute of Optoelectronics Fudan University Academy for Engineering and Technology Fudan University School of Information Science and Engineering Fudan University Microsystem and Terahertz Research Center Shanghai Institute of Intelligent electronics & Systems

三元过渡金属硫族化合物(TMDs)合金因其独特的光学和光电性能而备受关注,是光电子应用的理想候选者.目前对其量子约束效应和光电子响应特性还未全面了解.本项研究利用多种光谱测试分析方法来研究不同层数(4～11层)的MoSSe薄膜的光学性... 详细信息

三元过渡金属硫族化合物(TMDs)合金因其独特的光学和光电性能而备受关注,是光电子应用的理想候选者.目前对其量子约束效应和光电子响应特性还未全面了解.本项研究利用多种光谱测试分析方法来研究不同层数(4～11层)的MoSSe薄膜的光学性质和电子能带结构.研究结果揭示了拉曼模式的分裂及声子振动频率随着厚度的增加的移动,表明MoSSe在晶格内具有强烈的相互作用.A、B激子随层数增加的红移现象,证明了量子约束对激子性质和光学带隙的主导作用.制备的MoSSe光电探测器展现出了在350-800 nm范围内的宽光谱探测能力.其光电流和响应度随着薄膜厚度的增加而增强,极大凸显了基于MoSSe薄膜的光电探测器件在实际光电应用中的潜力.

关键词： MoSSe alloy quantum confinement effects exciton electronic band structure photodetection

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Exotic electronic states in the world of flat bands:From theory to material

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Chinese Physics B 2014年第7期23卷 1-12页

作者：刘峥刘锋吴咏时 Department of Materials Science and Engineering University of Utah Collaborative Innovation Center of Quantum Matter State Key Laboratory of Surface Physics and Department of Physics Fudan University Department of Physics and Astronomy University of Utah

It has long been noticed that special lattices contain single-electron flat bands （FB） without any dispersion. Since the kinetic energy of electrons is quenched in the FB, this highly degenerate energy level becomes an ideal platform to achieve strongly correlated electronic states, such as magnetism, superconductivity, and Wigner crystal. Recently, the FB has attracted increasing interest because of the possibility to go beyond the conventional symmetry-breaking phases towards topologically ordered phases, such as lattice versions of fractional quantum Hall states. This article reviews different aspects of FBs in a nutshell. Starting from the standard band theory, we aim to bridge the frontier of FBs with the textbook solid- state physics. Then, based on concrete examples, we show the common origin of FBs in terms of destructive interference, and discuss various many-body phases associated with such a singular band structure. In the end, we demonstrate real FBs in quantum frustrated materials and organometallic frameworks.

关键词： electronic band structure strongly-correlated electrons topological material

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electronic structure and optical properties of the red and yellow mercuric iodides

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Chinese Physics B 2010年第3期19卷 432-438页

作者：徐斌吕健 Department of Mathematics and Information Sciences North China Institute of Water Conservancy and Hydroelectric Power

With the help of the ab initio full-potential linearized augmented plane wave （FPLAPW） method, calculations of the electronic structure and linear optical properties are carried out for red HgI2 and yellow HgI2. It is found that the red HgI2 has a direct gap of 1.22834 eV and the yellow HgI2 has an indirect gap of 2.11222 eV. For the red HgI2, the calculated optical spectra are qualitatively in agreement with the experimental data. Furthermore, the origins of the different peaks of ε2（ω） are discussed. Our calculated anisotropic dielectric function of the red HgI2 is a nice match with the experimental results. Our calculated results are able to reproduce the overall trend of the experimental reflectivity spectra. Although no comparable experimental and theoretical results are available, clearly, the above proves the reliability of our calculations, suggesting that our calculations should be convincing for the yellow HgI2. Finally, the different optical properties are discussed.

关键词： ab initio electronic band structure optical properties semiconductor

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Density functional theory analysis of electronic structure and optical properties of La-doped Cd_2SnO_4 transparent conducting oxide

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Chinese Physics B 2018年第1期27卷 486-491页

作者：汤梅尚家香张跃 School of Materials Science & Engineering Beihang University Journal Publishing Center of Tsinghua University Press

The electronic structural, effective masses of carriers, and optical properties of pure and La-doped Cd2SnO4 are calculated by using the first-principles method based on the density functional theory. Using the GGA＋U method, we show that Cd2SnO4 is a direct band-gap semiconductor with a band gap of 2.216 eV, the band gap decreases to 2.02 eV and the Fermi energy level moves to the conduction band after La doping. The density of states of Cd2SnO4 shows that the bottom of the conduction band is composed of Cd 5s, Sn 5s, and Sn 5p orbits, the top of the valence band is composed of Cd 4d and O 2p, and the La 5d orbital is hybridized with the O 2p orbital, which plays a key role at the conduction band bottom after La doping. The effective masses at the conduction band bottom of pure and La-doped Cd2SnO4 are 0.18m0 and 0.092m0, respectively, which indicates that the electrical conductivity of Cd2SnO4 after La doping is improved. The calculated optical properties show that the optical transmittance of La-doped Cd2SnO4 is 92%, the optical absorption edge is slightly blue shifted, and the optical band gap is increased to 3.263 eV. All the results indicate that the conductivity and optical transmittance of Cd2SnO4 can be improved by doping La.

关键词： transparent conducting oxides electronic band structure first-principle calculations optical prop-erties

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Elastic, thermodynamic, electronic, and optical properties of recently discovered superconducting transition metal boride NbRuB:An ab-initio investigation

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Chinese Physics B 2017年第10期26卷 339-347页

作者： F Parvin S H Naqib Department of Physics University of Rajshahi

The elastic, thermodynamic, electronic, and optical properties of recently discovered and potentially technologically important transition metal boride NbRuB, are investigated using the density functional formalism. Both generalized gradient approximation （GGA） and local density approximation （LDA） are used for optimizing the geometry and for estimating various elastic moduli and constants. The optical properties of NbRuB are studied for the first time with different photon polarizations. The frequency （energy） dependence of various optical constants complement quite well the essential features of the electronic band structure calculations. Debye temperature of NbRuB is estimated from the thermodynamical study. All these theoretical estimates are compared with published results, where available, and discussed in detail. Both electronic band structure and optical conductivity reveal robust metallic characteristics. The NbRuB possesses significant elastic anisotropy. electronic features, on the other hand, are almost isotropic in nature. The effects of electronic band structure and Debye temperature on the emergence of superconductivity are also analyzed.

关键词： hard materials ternary borides DFT calculations electronic band structure optical properties superconductivity

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