Article
Materials Science, Multidisciplinary
Sergei Starikov, Vahid Jamebozorgi, Daria Smirnova, Ralf Drautz, Matous Mrovec
Summary: Screw and edge dislocations in body-centered cubic transition metals exhibit distinct diffusion characteristics, with the migration along screw dislocations being faster due to their different atomic structures.
Article
Multidisciplinary Sciences
Hyeon Han, Yaolong Xing, Bumsu Park, Dmitry Bazhanov, Yeongrok Jin, John T. S. Irvine, Jaekwang Lee, Sang Ho Oh
Summary: This study reveals the atomic-scale mechanism of nanoparticle formation in non-stoichiometric perovskite oxide, where excess B-site cations are accommodated by anti-phase boundaries and nanoparticles form through a two-step crystallization mechanism.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Naveen Kumar Tailor, Saurabh K. Saini, Pankaj Yadav, Mahesh Kumar, Soumitra Satapathi
Summary: Lead-free Cs2AgBiBr6 double perovskites show potential as an alternative to lead-based halide perovskites for photovoltaic and optoelectronic applications. This study reveals that the formation of small polarons and their localization limit the carrier dynamics in Cs2AgBiBr6 double-perovskite halide materials. The dominant conduction mechanism is found to be single polaron hopping. These findings provide important insights into the intrinsic limitations of Cs2AgBiBr6 perovskites and their applicability to other bismuth-based semiconductors.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Xuejiao Li, Lei Zhang, Liuming Yan, Meilin Liu, Zhongfeng Tang
Summary: In this study, reactive molecular dynamics simulations were used to investigate the defect structures and ion transport mechanism of yttrium-doped barium zirconate (BZY) electrolyte. The study found that a slightly elongated O-O distance in the hydrated system promotes proton hopping and the weak interaction between dopants and protons facilitates proton diffusion in the dislocation system. The dopant concentration and proton concentration were identified as important factors affecting proton conduction.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xihan Chen, Haipeng Lu, Kang Wang, Yaxin Zhai, Vladimir Lunin, Peter C. Sercel, Matthew C. Beard
Summary: Metal-halide perovskite semiconductors show potential for opto-spintronic applications by manipulating charge and spin degrees of freedom to reduce power consumption and achieve faster switching times. Tuning excitation density and exciton binding energy can lead to long spin lifetimes in these systems, with different mechanisms dominating at low and high excitation densities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Materials Science, Multidisciplinary
Shaan Bibi Jaffri, Khuram Shahzad Ahmad
Summary: The utilization of nanomaterials in optimizing perovskite solar cells to improve solar energy conversion efficiency and reduce reliance on silicon-based photovoltaic technology has shown progress. However, further research is needed to address issues such as synthetic costs, procedural complexities, and stability in order to fully realize the potential of nanocrystals and quantum dots in PSCs.
CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Jae-Hwan Kim, Young-Hwan Lee, Jun-Hyoung Park, Byeong-Joo Lee, Young-Woon Byeon, Jae-Chul Lee
Summary: Research shows that in the Na-Sn battery system, the generation of high-density dislocations in crystalline Sn relieves the residual stresses near the interface, facilitating the ultrafast diffusion of sodium into the Sn crystal and improving battery performance. Combining multi-scale simulations and molecular dynamics can help explain the structural origins of these ultrafast diffusion rates.
Article
Nanoscience & Nanotechnology
Zhaojue Lan, Linfeng Cai, Dan Luo, Furong Zhu
Summary: The distinct visible-blind narrowband near-infrared (NIR) photo-detection behaviors in the perovskite/polymer hybrid photodetectors (PDs) have been investigated. The semiconducting perovskite layer acts as an internal NIR bandpass due to its high absorption to the visible light and high transparency to the NIR light. The hybrid PDs demonstrated have a -3 dB cutoff frequency of 300 kHz, providing an exciting option for a plethora of applications in bioimaging, environmental detection, and security monitoring.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Multidisciplinary Sciences
Zeyu Zhang, Qingde Sun, Yue Lu, Feng Lu, Xulin Mu, Su-Huai Wei, Manling Sui
Summary: The authors report hydrogenated lead-free inorganic perovskite solar cells with enhanced power conversion efficiency. By using a hydrogenation method, the bandgap of Cs2AgBiBr6 films could be tunable from 2.18 eV to 1.64 eV, resulting in improved photoelectric conversion efficiency of the solar cells.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
XiuXiu Feng, Jiyao Wei, Xiaodong Li, Wenxiao Zhang, Xiaoyan Zhao, Chunyan Lu, Xuemin Guo, Junfeng Fang
Summary: By combining PbI2 with TMB to form the TMB-PbI2 radical, the conductivity is increased by 4 orders of magnitude, leading to an impressive increase in device performance from 20.48% to 22.63%. Moreover, the device stability is greatly improved, with 95% of the initial efficiency retained after aging at 85 degrees C for 600 hours.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Mechanical
Xiaohua Niu, Yang Xiang, Xiaodong Yan
Summary: This paper presents a phase field model for simulating the self-climb motion of prismatic dislocation loops via vacancy pipe diffusion driven by elastic interactions. The model has the advantage of automatically handling topological and geometrical changes, and numerical simulations show excellent agreement with experimental observations.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Physical
Xin Xu, Connor Carr, Xinqi Chen, Benjamin D. Myers, Ruiyun Huang, Weizi Yuan, Sihyuk Choi, Dezhi Yi, Charudatta Phatak, Sossina M. Haile
Summary: This study reveals the variation in grain boundary properties of polycrystalline ionic materials and the correlation between grain boundary resistance and impurity concentration. The findings suggest that the grain boundary resistance may be caused by impurity-generated space charge effects and driven by the energetics of impurity segregation.
ADVANCED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Elisabeth Robens, Robert Rauschen, Johannes Kaub, Jana P. Parras, Dennis Kemp, Colin L. Freeman, Roger A. De Souza
Summary: In this study, molecular dynamics simulations were used to calculate oxygen diffusion coefficients in CaTiO3 with different crystal structures, revealing higher activation enthalpy for oxygen diffusion in the orthorhombic structure compared to the cubic structure. The presence of acceptor-type cation defects was found to negatively impact oxygen diffusion, especially in low-symmetry structures. The results provide insights into experimental transport studies, trends for alkaline-earth perovskites, and highlight the advantages of using MD simulations for studying ion migration in distorted perovskite structures.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
Marie Landeiro Dos Reis, Yvelin Giret, Philippe Carrez, Patrick Cordier
Summary: This study investigates the mechanisms of pipe diffusion and point defect diffusion along dislocation line in MgO. Through numerical calculations and the use of elasticity theory, the migration energies of point defects are determined. The diffusion kinetics near the dislocation is evaluated using an on-lattice atomistic kinetic Monte Carlo algorithm based on atomistic simulations. The study reveals that the edge dislocation in MgO acts as a strong sink for vacancies, leading to enhanced diffusion of point defects near the dislocation.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Physics, Applied
Francisco Pena-Camargo, Jarla Thiesbrummel, Hannes Hempel, Artem Musiienko, Vincent M. Le Corre, Jonas Diekmann, Jonathan Warby, Thomas Unold, Felix Lang, Dieter Neher, Martin Stolterfoht
Summary: Traditional inorganic semiconductors can be electronically doped with high precision, but the assessment and control of electronic doping density in metal-halide perovskites still remain uncertain. This study presents a multifaceted approach using optical and electrical characterization techniques to quantify the electronic doping density for various lead-halide perovskite systems. The results indicate that the doping density in common lead-based metal-halide perovskites is below the critical threshold of 10(12) cm(-3), which does not affect the device performance.
APPLIED PHYSICS REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Kendra S. Belthle, Ute N. Gries, Michael P. Mueller, Dennis Kemp, Abhinav Prakash, Marc-Andre Rose, Jacqueline M. Boergers, Bharat Jalan, Felix Gunkel, Roger A. De Souza
Summary: The properties and concentrations of native point defects in the perovskite oxide BaSnO3 were studied using a combination of experiments and simulations. The results provide insights into the material's characteristics and stability.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Hans F. Wardenga, Katharina N. S. Schuldt, Stephan Waldow, Roger A. De Souza, Andreas Klein
Summary: The study investigated the influence of different doping methods, concentrations, and surface orientations on the surface Fermi level positions, ionisation potentials, and work functions of CeO2. It was found that the ionisation potentials are significantly affected by doping and oxygen activity, while the work functions are largely unaffected. In terms of oxygen surface exchange coefficients, similar magnitudes were observed under different conditions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Elisabeth Robens, Robert Rauschen, Johannes Kaub, Jana P. Parras, Dennis Kemp, Colin L. Freeman, Roger A. De Souza
Summary: In this study, molecular dynamics simulations were used to calculate oxygen diffusion coefficients in CaTiO3 with different crystal structures, revealing higher activation enthalpy for oxygen diffusion in the orthorhombic structure compared to the cubic structure. The presence of acceptor-type cation defects was found to negatively impact oxygen diffusion, especially in low-symmetry structures. The results provide insights into experimental transport studies, trends for alkaline-earth perovskites, and highlight the advantages of using MD simulations for studying ion migration in distorted perovskite structures.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Editorial Material
Chemistry, Physical
Stephen J. Skinner, Viola Birss, Jennifer Rupp, Roger A. De Souza
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Alexander F. Zurhelle, Wilhelm Stehling, Rainer Waser, Roger A. De Souza, Stephan Menzel
Summary: The study investigates the diffusion of oxygen atoms in platinum crystals and along its extended defects using molecular dynamics simulations. The research suggests that producing specific electrode microstructures with controlled densities and types of extended defects can enhance the performance of ReRAM devices and prevent device failure.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Physical
Joe Kler, Roger A. De Souza
Summary: This study demonstrates an indirect method to probe the thermodynamics of water incorporation, using perovskite oxide samples subjected to H218O/H216O exchange annealing.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Energy & Fuels
Francesco M. Chiabrera, Federico Baiutti, Jacqueline M. Boergers, George F. Harrington, Lluis Yedra, Maciej O. Liedke, Joe Kler, Pranjal Nandi, Juan de Dios Sirvent, Jose Santiso, Miguel Lopez-Haro, Jose J. Calvino, Sonia Estrade, Maik Butterling, Andreas Wagner, Francesca Peiro, Roger A. De Souza, Albert Tarancon
Summary: This study investigates the impact of Mn deficiency on oxygen mass transport properties in perovskite oxides, and highlights the importance of antisite defects in mitigating the effects of nonstoichiometry on oxygen transport.
JOURNAL OF PHYSICS-ENERGY
(2022)
Article
Chemistry, Physical
Roger A. De Souza, Dennis Kemp, Matthew J. Wolf, Amr H. H. Ramadan
Summary: The activation energies of defect migration in ABX3 perovskite halides obtained through static supercell calculations are unreliable, particularly at temperatures relevant to device operation, due to the adoption of higher symmetry structures and local structural modifications in addition to ion relaxation around the point defects. We propose a robust test to determine the reliability of static supercell calculations for point defect processes in ABX3 perovskite systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Joe Kler, Jacqueline M. Borgers, Roger A. De Souza
Summary: The effect of surface orientation on oxygen surface exchange coefficient and surface space-charge potential in single-crystal SrTiO3 is studied. The results show that surface orientation has a significant influence on these properties.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Sylvia Koerfer, Alexander Bonkowski, Joe Kler, Peter Hatton, Blas Pedro Uberuaga, Roger A. De Souza
Summary: In this study, cation diffusion in fluorite-structured CeO2 is investigated using classical molecular dynamics and metadynamics simulations. It is found that cation diffusion primarily occurs through cation divacancies, rather than isolated vacancies or cation vacancy-oxygen vacancy associates.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Adrian L. Usler, Dennis Kemp, Alexander Bonkowski, Roger A. De Souza
Summary: Analysis of the mean squared displacement of species k as a function of simulation time allows the extraction of tracer diffusion coefficient from a molecular dynamics simulation. The statistical error in the diffusion coefficient is often underestimated. In this study, we examined the statistics of displacement curves generated by solid-state diffusion and derived a closed-form expression for the relative uncertainty in the diffusion coefficient.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Roger De Souza, George Harrington
Summary: The study of point defects in non-metallic crystals is important for various materials applications. Consistent definitions and terminology are necessary for progress in this field. This Comment clarifies the definitions of point defects, advocates for the correct use of relative charge in their description, and emphasizes their recognition as quasiparticles.
Article
Chemistry, Physical
Alexander Bonkowski, Caitlin Perkampus, Roger A. De Souza
Summary: By molecular dynamics simulations, we predict that substituting Ba with Ca yields a material, Ca0.5Sr0.5Co0.8Fe0.2O3-delta, that exhibits similarly high oxygen-vacancy diffusivity in its cubic form.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Roger A. De Souza, Dennis Kemp, Matthew J. Wolf, Amr H. H. Ramadan
Summary: The activation energies of defect migration in ABX3 perovskite halides obtained through static supercell calculations may be unreliable at temperatures relevant to device operation due to local structural modifications. A robust test method is proposed to determine the reliability of static supercell calculations in point defect processes in perovskite systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Dennis Kemp, Albert Tarancon, Roger A. De Souza
Summary: In this study, we used MD and MMC simulations to determine the oxide-ion mobility in Ce1-yGdyO2-y/2 materials and proposed an analytical model to interpret the results. The findings suggest that higher oxide-ion conductivity can be achieved through non-equilibrium deposition and nanoscale-thick samples.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)