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Liu G, Gao T, Huang J, Yan W, Xie Q, Xiao Q. Exploring Defect Dynamics and Twin-Layer Interactions in SiC Crystals through Molecular Simulations. J Phys Chem B 2024; 128:7848-7858. [PMID: 39086234 DOI: 10.1021/acs.jpcb.4c03117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
Silicon carbide (SiC), a third-generation semiconductor material, is pivotal for applications in new energy vehicles, aerospace, and high-speed electronics, owing to its superior properties. This study delves into the twin-induced growth behaviors of SiC crystals through molecular dynamics simulations at temperatures ranging from 2700 to 3200 K. It focuses on the wurtzite and zinc blende SiC structures, revealing dynamic defect behavior during growth, including an initial rise and subsequent decrease in vacancies, with particular emphasis on prevalent defects within zinc blende twin layers. A significant finding is the direct correlation between temperature and growth rates across different SiC structures, highlighting temperature control as essential for optimizing crystal quality. Furthermore, this work contributes to the analysis of the interactions of twin layers and their impact on structural stability and defect formation in SiC crystals. The insights gained here have substantial implications for the semiconductor industry, potentially enhancing device performance by better controlling growth conditions and defect management in SiC-based electronic and optoelectronic devices.
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Affiliation(s)
- Guiyang Liu
- Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
| | - Tinghong Gao
- Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
| | - Jin Huang
- Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
| | - Wanjun Yan
- College of Electronic & Information Engineering, Anshun University, Anshun 56100, China
| | - Quan Xie
- Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
| | - Qingquan Xiao
- Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
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Bonmassar N, Christiani G, Logvenov G, Suyolcu YE, van Aken PA. Offcut Substrate-Induced Defect Trapping at Step Edges. NANO LETTERS 2024; 24:5556-5561. [PMID: 38668651 PMCID: PMC11082922 DOI: 10.1021/acs.nanolett.4c00832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
We report step edge-induced localized defects suppressing subsequent antiphase boundary formation in the bulk structure of a trilayer oxide heterostructure. The heterostructure encompasses a layer of La0.66Sr0.34MnO3 sandwiched between a superconducting La1.84Sr0.16CuO4 bottom layer and an insulating La2CuO4 top layer. The combination of a minor a-axis mismatch (0.11 Å) and a pronounced c-axis mismatch (2.73 Å) at the step edges leads to the emergence of localized defects exclusively forming at the step edge. Employing atomically resolved electron energy-loss spectroscopy maps, we discern the electronic state of those structures in the second La0.66Sr0.34MnO3 unit cell near the step edge. In particular, a reduction in the pre-edge region of the O-K edge indicates the formation of oxygen vacancies induced by the strained step edge. This study underscores our capability to control defects at the nanoscale.
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Affiliation(s)
- Nicolas Bonmassar
- Max Planck Institute for Solid State
Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Georg Christiani
- Max Planck Institute for Solid State
Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Gennady Logvenov
- Max Planck Institute for Solid State
Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Y. Eren Suyolcu
- Max Planck Institute for Solid State
Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Peter A. van Aken
- Max Planck Institute for Solid State
Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
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Liu X, Liu X, Li C, Yang B, Wang L. Defect engineering of electrocatalysts for metal-based battery. CHINESE JOURNAL OF CATALYSIS 2023. [DOI: 10.1016/s1872-2067(22)64168-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Waqar M, He Q, Chai J, Lim PC, Yao K, Wang J. Diverse Defects in Alkali Niobate Thin Films: Understanding at Atomic Scales and Their Implications on Properties. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2205137. [PMID: 36433826 DOI: 10.1002/smll.202205137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/30/2022] [Indexed: 06/16/2023]
Abstract
Defects in ferroelectric materials have many implications on the material properties which, in most cases, are detrimental. However, engineering these defects can also create opportunities for property enhancement as well as for tailoring novel functionalities. To purposely manipulate these defects, a thorough knowledge of their spatial atomic arrangement, as well as elastic and electrostatic interactions with the surrounding lattice, is highly crucial. In this work, analytical scanning transmission electron microscopy (STEM) is used to reveal a diverse range of multidimensional crystalline defects (point, line, planar, and secondary phase) in (K,Na)NbO3 (KNN) ferroelectric thin films. The atomic-scale analyses of the defect-lattice interactions suggest strong elastic and electrostatic couplings which vary among the individual defects and correspondingly affect the electric polarization. In particular, the observed polarization orientations are correlated with lattice relaxations as well as strain gradients and can strongly impact the properties of the ferroelectric films. The knowledge and understanding obtained in this study open a new avenue for the improvement of properties as well as the discovery of defect-based functionalities in alkali niobate thin films.
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Affiliation(s)
- Moaz Waqar
- Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117574, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, 119077, Singapore
| | - Qian He
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117574, Singapore
| | - Jianwei Chai
- Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
| | - Poh Chong Lim
- Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
| | - Kui Yao
- Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, 119077, Singapore
| | - John Wang
- Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117574, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, 119077, Singapore
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Arandiyan H, S Mofarah S, Sorrell CC, Doustkhah E, Sajjadi B, Hao D, Wang Y, Sun H, Ni BJ, Rezaei M, Shao Z, Maschmeyer T. Defect engineering of oxide perovskites for catalysis and energy storage: synthesis of chemistry and materials science. Chem Soc Rev 2021; 50:10116-10211. [PMID: 34542117 DOI: 10.1039/d0cs00639d] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Oxide perovskites have emerged as an important class of materials with important applications in many technological areas, particularly thermocatalysis, electrocatalysis, photocatalysis, and energy storage. However, their implementation faces numerous challenges that are familiar to the chemist and materials scientist. The present work surveys the state-of-the-art by integrating these two viewpoints, focusing on the critical role that defect engineering plays in the design, fabrication, modification, and application of these materials. An extensive review of experimental and simulation studies of the synthesis and performance of oxide perovskites and devices containing these materials is coupled with exposition of the fundamental and applied aspects of defect equilibria. The aim of this approach is to elucidate how these issues can be integrated in order to shed light on the interpretation of the data and what trajectories are suggested by them. This critical examination has revealed a number of areas in which the review can provide a greater understanding. These include considerations of (1) the nature and formation of solid solutions, (2) site filling and stoichiometry, (3) the rationale for the design of defective oxide perovskites, and (4) the complex mechanisms of charge compensation and charge transfer. The review concludes with some proposed strategies to address the challenges in the future development of oxide perovskites and their applications.
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Affiliation(s)
- Hamidreza Arandiyan
- Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia. .,Centre for Applied Materials and Industrial Chemistry (CAMIC), School of Science, RMIT University, 124 La Trobe Street, Melbourne, VIC, Australia.
| | - Sajjad S Mofarah
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - Charles C Sorrell
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - Esmail Doustkhah
- National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Baharak Sajjadi
- Department of Chemical Engineering, University of Mississippi, University, MS, 38677, USA
| | - Derek Hao
- School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Yuan Wang
- Centre for Applied Materials and Industrial Chemistry (CAMIC), School of Science, RMIT University, 124 La Trobe Street, Melbourne, VIC, Australia. .,School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Hongyu Sun
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Bing-Jie Ni
- School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Mehran Rezaei
- Catalyst and Nanomaterials Research Laboratory (CNMRL), School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Zongping Shao
- WA School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Perth, WA 6845, Australia. .,State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Thomas Maschmeyer
- Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia.
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Yun H, Topsakal M, Prakash A, Jalan B, Jeong JS, Birol T, Mkhoyan KA. Metallic line defect in wide-bandgap transparent perovskite BaSnO 3. SCIENCE ADVANCES 2021; 7:7/3/eabd4449. [PMID: 33523903 PMCID: PMC7810381 DOI: 10.1126/sciadv.abd4449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
A line defect with metallic characteristics has been found in optically transparent BaSnO3 perovskite thin films. The distinct atomic structure of the defect core, composed of Sn and O atoms, was visualized by atomic-resolution scanning transmission electron microscopy (STEM). When doped with La, dopants that replace Ba atoms preferentially segregate to specific crystallographic sites adjacent to the line defect. The electronic structure of the line defect probed in STEM with electron energy-loss spectroscopy was supported by ab initio theory, which indicates the presence of Fermi level-crossing electronic bands that originate from defect core atoms. These metallic line defects also act as electron sinks attracting additional negative charges in these wide-bandgap BaSnO3 films.
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Affiliation(s)
- Hwanhui Yun
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mehmet Topsakal
- Nuclear Science and Technology Department, Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Abhinav Prakash
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Bharat Jalan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jong Seok Jeong
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
- Analytical Sciences Center, LG Chem Ltd., Daejeon, Republic of Korea
| | - Turan Birol
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - K Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
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Li C, Song D, Li M, Tang C, Xue D, Wan D, Pennycook SJ. Atomic scale characterization of point and extended defects in niobate thin films. Ultramicroscopy 2019; 203:82-87. [PMID: 30857652 DOI: 10.1016/j.ultramic.2019.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/22/2019] [Accepted: 03/03/2019] [Indexed: 11/29/2022]
Abstract
Niobium-based oxides have a wide range of applications owing to their rich crystal and electronic structures. Defects at the atomic scale are always unavoidable and will affect their functionalities, especially when in the form of thin films. Here, atomic resolution scanning transmission electron microscopy and electron energy loss spectroscopy have been performed on various defects (point, line, planar defects and segregated phases) in alkaline and alkaline-earth niobate thin films: CaZrO3 modified (K, Na)NbO3 and strontium niobate (SNO), respectively. In CaZrO3 modified (K,Na)NbO3 thin films, a tetragonal tungsten bronze phase was found, with a sharp boundary with the perovskite phase. In SNO thin films, several kinds of point defects and antiphase boundaries are commonly observed. In addition, a strongly Sr deficient phase, SrNb2O6, precipitates inside the SrNbO3 phase with a coherent interface. The different oxidation states of Nb in SrNbO3 and SrNb2O6 were revealed from the O K edge. Our characterization of the point defects and extended defects in niobate thin films offers practical guidelines for thin film deposition or discovery of defect-based novel functionalities.
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Affiliation(s)
- Changjian Li
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - Dongsheng Song
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore; NUSNNI-Nanocore, National University of Singapore, 117411 Singapore.
| | - Mengsha Li
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - Chunhua Tang
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - Deqing Xue
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - Dongyang Wan
- NUSNNI-Nanocore, National University of Singapore, 117411 Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore; NUSNNI-Nanocore, National University of Singapore, 117411 Singapore.
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Ong PV, Du Y, Sushko PV. Low-Dimensional Oxygen Vacancy Ordering and Diffusion in SrCrO 3-δ. J Phys Chem Lett 2017; 8:1757-1763. [PMID: 28365995 DOI: 10.1021/acs.jpclett.7b00355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigate the formation mechanisms of vacancy-ordered phase and collective mass transport in epitaxial SrCrO3-δ films using ab initio simulations within the density functional theory formalism. We show that as the concentration of oxygen vacancies (VO) increases, they form 1D chains that feature Cr-centered tetrahedra. Aggregation of these 1D VO chains results in the formation of (111)-oriented oxygen-deficient planes and an extended vacancy-ordered phase observed in recent experiments. We discuss atomic-scale mechanisms enabling the quasi-2D VO aggregates to expand along and translate across (111) planes. The corresponding lowest activation energy pathways necessarily involve rotation of Cr-centered tetrahedra, which emerges as a universal feature of fast ionic conduction in complex oxides. These findings explain reversible oxidation and reduction in SrCrO3-δ at low temperatures and provide insights into transient behavior necessary to harness ionic conductive oxides for high-performance and low-temperature electrochemical reactors.
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Affiliation(s)
- Phuong-Vu Ong
- Physical Sciences Division, Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Yingge Du
- Physical Sciences Division, Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Peter V Sushko
- Physical Sciences Division, Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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