Article
Chemistry, Multidisciplinary
Jesus Canas, Daniel F. Reyes, Alter Zakhtser, Christian Dussarrat, Takashi Teramoto, Marina Gutierrez, Etienne Gheeraert
Summary: The synthesis development of silicon oxide atomic layer deposition has opened the possibility of using it as a dielectric material in diamond electronics. The study of the heterojunction between deposited silicon oxide and oxygen-terminated diamond has provided insights into the properties and interface of the materials.
Article
Chemistry, Multidisciplinary
Mario Pelaez-Fernandez, Yung-Chang Lin, Kazu Suenaga, Raul Arenal
Summary: Band gap engineering of atomically thin two-dimensional (2D) materials has garnered much interest for their potential applications in nanooptoelectronics and nanophotonics. Low-loss electron energy loss spectroscopy was used to directly measure the band gap in atomically thin Mo(x)W((1-x))S2 nanoflakes, revealing a bowing effect with the alloying degree. The study also analyzed additional properties such as Van Hove singularities in the density of states and high energy excitonic transitions in these materials.
Article
Physics, Applied
Mohsen Yarmohammadi, Kavoos Mirabbaszadeh
Summary: This study theoretically investigates the changes in band gap and EELS function when black phosphorene is coupled with a magnetic material with rotating magnetization. The results show that the amplitude of EELS is inversely proportional to the band gap changes induced by the rotating exchange field, with peak positions in EELS function corresponding to the modified band gaps. This research highlights the importance of manipulating anisotropic interband optical excitations in phosphorene through magnetic perturbations for various optoelectronic applications.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
J. E. Leal-Perez, G. Herrera-Perez, G. Umoh, A. Hurtado-Macias
Summary: Sb-doped KNN is an environmentally-friendly lead-free ferroelectric with high piezoelectric response. In this study, the band gap energy, complex dielectric function, and optical properties of KNNS were evaluated. Understanding the applications of KNNS in optoelectronic devices is crucial, and the relativistic effects are often overlooked in related measurements.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Polymer Science
Ruchi Pal, Arun K. Sikder, Kei Saito, Alison M. Funston, Jayesh R. Bellare
Summary: Polymer blends are important for both commercial utility and scientific understanding, and the degree of interfacial mixing in these blends influences their mechanical properties. This paper introduces a method using scanning transmission electron microscopy spectrum imaging to calculate the interfacial width in immiscible polymer blends and demonstrates its application using a polycarbonate-polystyrene bilayer sample as an example.
POLYMER INTERNATIONAL
(2023)
Article
Microscopy
Pavel Potapov, Axel Lubk
Summary: This article presents a new method using Multivariate Statistical Analysis to extract physically meaningful information from STEM EELS and EDX spectrum images, combining geometric and statistical approaches to find endmembers. The algorithm is described in detail with an example of EELS spectrum-imaging of a CMOS transistor.
Article
Materials Science, Multidisciplinary
Hassan Gezzaz, Cristiana L. Ciobanu, Ashley Slattery, Nigel J. Cook, Kathy Ehrig
Summary: We investigated cation disorder in inverse spinels like magnetite using atomic-scale scanning transmission electron microscopy and electron energy loss spectroscopy. Our findings reveal that fast cooling from high temperature results in minor partial ordering and influences the behavior of trace elements in magnetite. This research has implications for thermodynamic modeling of material stability and the transformation of industrial waste into valuable resources.
MATERIALS CHARACTERIZATION
(2023)
Article
Microscopy
Yun-Yu Wang, Qiang Jin, Kent Zhuang, Jae Kyu Choi, Jochonia Nxumalo
Summary: This study presents a method for measuring energy band gaps based on nano-beam STEM and small off-axis angle valence band TEELS, effectively eliminating the impact of multiple scattering events through self-convolution method, accurately calculating the dielectric function, and obtaining optical band gap results independent of sample thickness. The TEELS band gap data obtained are consistent with those from REELS measurements.
Article
Chemistry, Physical
Amalia Navarro, Elisa Garcia-Tabares, Quentin M. Ramasse, Pablo Cano, Ignacio Rey-Stolle, Beatriz Galiana
Summary: Integration of GaP layers on silicon substrates using AsH3 pre-exposure followed by a PH3-based GaP epitaxial growth allows the development of very promising processes for the photovoltaic industry. However, many of the growth routines using this approach suffer from reproducibility issues, leading to poor quality layers. This lack of knowledge on the mechanisms behind the formation of common planar defects and their dynamics hinders the successful transfer of the method to new epitaxial systems.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
ChenChao Fang, Ning Wang, Xiangying Shen
Summary: The study investigates the vibrational modes of distorted square lattice networks and finds a gap between the two lowest modes correlated to the twisting angle. The results may have applications in device protection and energy harvesting.
RESULTS IN PHYSICS
(2021)
Article
Microscopy
Chisaki Iwashimizu, Mitsutaka Haruta, Takashi Nemoto, Hiroki Kurata
Summary: In this study, high-angle annular dark-field (HAADF) imaging and elemental mapping by scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) were used to investigate rutile TiO2. Unexpected image contrast was observed in the elemental mapping, showing an anisotropic elliptical shape along the long axis in the octahedral structure, while the atomic contrast of Ti columns in the HAADF image was almost circular. Multi-slice simulation revealed that unique electron channeling related to the rutile structure and the difference in potentials between HAADF and EELS caused the different atomic contrasts in the two images.
Article
Chemistry, Physical
Hemali Rathnayake, Sujoy Saha, Sheeba Dawood, Shane Loeffler, Joseph Starobin
Summary: A rapid and simple analytical approach has been developed to screen the semiconducting properties of metal organic frameworks (MOFs) by modeling band structure and predicting density of state. This method allows for quick identification of potential semiconducting MOFs by analyzing electronic structures and density of state based on experimental spectroscopic data.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Multidisciplinary Sciences
M. Jansson, V. V. Nosenko, G. Yu Rudko, F. Ishikawa, W. M. Chen, I. A. Buyanova
Summary: In this study, the effects of Bi incorporation on lattice dynamics and carrier recombination processes in GaAs/GaAsBi core/shell nanowires were investigated. It was found that increasing the Bi-beam equivalent pressure did not necessarily result in a higher alloy composition but significantly affected the carrier localization in GaAsBi. The bandgap of the Bi-containing shell remained practically independent of the Bi BEP, while the emission spectra of the nanowires experienced a significant red shift under increased Bi supply as a result of the localization effect.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Multidisciplinary
Nikita V. Tepliakov, Johannes Lischner, Efthimios Kaxiras, Arash A. Mostofi, Michele Pizzochero
Summary: In this study, a new perspective on the electronic structure of armchair graphene nanoribbons is presented using simple model Hamiltonians and ab initio calculations. The research demonstrates that the energy-gap opening in these nanoribbons is caused by the breaking of a hidden symmetry through long-ranged hopping of pi electrons and structural distortions at the edges. This hidden symmetry can be restored or manipulated through in-plane lattice strain, enabling continuous energy-gap tuning, the emergence of Dirac points at the Fermi level, and topological quantum phase transitions. This work establishes an original interpretation of the semiconducting properties of armchair graphene nanoribbons and provides guidelines for their rational electronic structure design.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Bernat Mundet, Claribel Dominguez, Jennifer Fowlie, Marta Gibert, Jean-Marc Triscone, Duncan T. L. Alexander
Summary: In this study, nanoscale mapping of the distinct electronic phases characterizing the metal-insulator transition displayed by rare-earth nickelate compounds was achieved using scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. The evolution of fine structures at O K and Ni L edges across different NdNiO3/SmNiO3 superlattices was tracked, revealing electronic states and spatial configurations of metallic/insulating regions. The width of metallic/insulating boundaries at the NdNiO3/SmNiO3 interfaces was estimated to be approximately four unit cells.
Article
Chemistry, Multidisciplinary
Sigurd Oien-Odegaard, Calliope Bazioti, Evgeniy A. Redekop, Oystein Prytz, Karl Petter Lillerud, Unni Olsbye
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Multidisciplinary Sciences
J. Smalc-Koziorowska, J. Moneta, P. Chatzopoulou, I. G. Vasileiadis, C. Bazioti, O. Prytz, I. Belabbas, Ph. Komninou, G. P. Dimitrakopulos
SCIENTIFIC REPORTS
(2020)
Article
Physics, Applied
X. Song, H. Riis, O. Prytz, T. G. Finstad
Summary: The study investigated the electrical resistance of ZnSb with different doping concentrations and annealing temperatures, revealing a systematic dependence on transport mechanisms at the metal- semiconductor interface. The research also measured the carrier concentration of ZnSb. The results were analyzed by a model incorporating various transport mechanisms at the interface.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
B. L. Aarseth, C. S. Granerod, A. Galeckas, A. Azarov, P. D. Nguyen, O. Prytz, L. Vines
Summary: Semiconductor nanocrystals are considered a feasible approach to enhance solar energy conversion in photovoltaics and photoelectrochemical systems. By embedding semiconducting nanocrystals with a small bandgap in a transparent conducting oxide, such as zinc oxide, the photon absorption and charge carrier transfer can be promoted, leading to improved function of the electrode. The incorporation, formation, and functionalization of germanium nanocrystals in zinc oxide have been demonstrated through ion implantation, with post-implantation annealing resulting in diamond cubic Ge nanocrystals and distinctive photoluminescence spectra. The novel functionalization and tunability of the TCO electrode is showcased through emission features up to 1.15 eV due to quantum confinement.
Article
Physics, Applied
S. B. Kjeldby, A. Azarov, P. D. Nguyen, V. Venkatachalapathy, R. Miksova, A. Mackova, A. Kuznetsov, O. Prytz, L. Vines
Summary: Defect accumulation and annealing phenomena in Si-implanted monoclinic gallium oxide wafers were studied using RBS/c, XRD, and (S)TEM. The accumulation of radiation disorder was found to be accompanied by strain accumulation, resulting in crystalline-to-crystalline phase transitions. Annealing of selected samples showed complex structural transformations, which were influenced by the fluence and temperature.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Xiaolan Kang, Vilde Mari Reinertsen, Kevin Gregor Both, Augustinas Galeckas, Thomas Aarholt, Oystein Prytz, Truls Norby, Dragos Neagu, Athanasios Chatzitakis
Summary: There is a growing demand to control and enhance the stability and efficacy of nanoparticles (NPs) for photo- and electrochemical energy conversion applications. The galvanic replacement/deposition method offers a simpler and safer approach to produce a wide range of hybrid nanostructures with increased tailorability. These bimetallic nanostructures, supported on SrTiO3, show exceptional activity in plasmon-assisted photoelectrochemical water oxidation reactions.
Article
Chemistry, Multidisciplinary
Nina S. Genz, Antti-Jussi Kallio, Ramon Oord, Frank Krumeich, Anuj Pokle, Oystein Prytz, Unni Olsbye, Florian Meirer, Simo Huotari, Bert M. Weckhuysen
Summary: Laboratory-based X-ray absorption spectroscopy (XAS) has potential applications in catalyst characterization. By designing a laboratory setup, we performed operando XANES analysis at multiple K-edges, studying the properties of mono-, bi-, and trimetallic CO2 hydrogenation catalysts containing Ni, Fe, and Cu. The results revealed significant metal-dependent differences in reducibility, re-oxidation behavior, and catalytic performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Annett Thogersen, Xinwei Sun, Ingvild Thue Jensen, Oystein Prytz, Truls Norby
Summary: The study demonstrates that CeO2 surfaces are reduced to a layer of oxyhydroxide by hydrogen-containing molecules during heating in vacuum, a process that occurs for all samples but is more pronounced for particles previously dispersed in ethanol.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Physics, Applied
J. Garcia-Fernandez, S. B. Kjeldby, P. D. Nguyen, O. B. Karlsen, L. Vines, O. Prytz
Summary: This study investigates the phase transformation and crystal structure of β-Ga2O3 samples induced by ion implantation using electron diffraction and various microscopy techniques. It reveals that the monoclinic β-phase transforms into the cubic γ-phase, contrary to previous reports. The transformation is found to be a general phenomenon due to strain accumulation and energetic preference.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Reshma K. Madathil, Vincent Thoreton, Oystein Prytz, Truls Norby
Summary: Thermoelectric ZnSb has a native surface oxide layer of Sb2O5 +ZnO. High-temperature oxidation in air results in selective oxidation to ZnO, with no detectable Sb by STEM-EDS. The oxidation process follows parabolic kinetics and is influenced by both Zn and O diffusion through the protective ZnO layer.
Article
Physics, Condensed Matter
Annett Thogersen, Ingvild J. T. Jensen, Branson D. Belle, Marit Stange, Vilde Mari Reinertsen, Torunn Kjeldstad, Oystein Prytz, Edouard Monakhov, Demie Kepaptsoglou
Summary: Plasmonic properties of aluminium nanowires in the UV and far UV region were investigated in this study. The study demonstrated that aluminium nanowires can serve as an excellent alternative to Ag or Au for enhancing optical activity. The size and spacing of the nanowires, as well as the embedding material, were found to significantly impact the type of surface plasmon energies that can be generated.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
Alexander Azarov, Javier Garcia Fernandez, Junlei Zhao, Flyura Djurabekova, Huan He, Ru He, Oystein Prytz, Lasse Vines, Umutcan Bektas, Paul Chekhonin, Nico Klingner, Gregor Hlawacek, Andrej Kuznetsov
Summary: The γ/β double polymorph Ga2O3 structures demonstrate exceptionally high radiation tolerance, tolerating disorder equivalent to hundreds of displacements per atom. This discovery highlights a new class of radiation tolerant semiconductors.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
S. Montag, D. Splith, M. Kneiss, M. Grundmann, J. Garcia Fernandez, O. Prytz, H. von Wenckstern
Summary: The structural, morphological, and optical properties of (In1-xGax)(2)O-3 thin films are investigated as a function of the cation composition. The lattice constant and absorption edge energy decrease and increase, respectively, with increasing Ga content up to a certain point. Moreover, the surface morphology of the films undergoes significant changes at certain Ga content.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
S. B. Kjeldby, P. D. Nguyen, J. Garcia-Fernandez, K. Haug, A. Galeckas, I. J. T. Jensen, A. Thogersen, L. Vines, O. Prytz
Summary: The efficiency of solar cells can be enhanced by utilizing tandem cells with different band gaps. By embedding semiconducting nanoparticles in a transparent conducting oxide (TCO) solar cell, the TCO layer can directly participate in photovoltaic conversion, contributing to enhanced absorption. The functional properties of ZnFe2O4 arise from the local structural similarity around Fe ions in spinel ZnFe2O4 and at Fe-decorated basal IDBs, leading to improved luminescence.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
G. C. Vasquez, M. E. Bathen, A. Galeckas, C. Bazioti, K. M. Johansen, D. Maestre, A. Cremades, O. Prytz, A. M. Moe, A. Yu Kuznetsov, L. Vines
Article
Microscopy
C. Gao, C. Hofer, T. J. Pennycook
Summary: Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, contrast reversals can occur when the projected potential becomes strong. Recent research has shown that these reversals can be counteracted by adapting the focus. This study explains why the best contrast is often found with the probe focused to the middle of the sample and highlights the importance of convergence angle in thin samples to remove contrast reversals.
Article
Microscopy
J. Lindner, U. Ross, T. Meyer, V. Boureau, M. Seibt, Ch. Jooss
Summary: Phase-shifting electron holography is an excellent method with high phase sensitivity to reveal electron wave phase information. An advanced drift correction scheme is proposed in this study, which exploits the interface of the TEM specimen and the vacuum area in the hologram. This method allows for obtaining reliable phase information.
Article
Microscopy
Ali Jaberi, Nicolas Brodusch, Jun Song, Raynald Gauvin
Summary: This study investigates knock-on damage in lithium-ion batteries (LIBs) by computing threshold displacement energies (TDEs) and performing Monte Carlo simulation. The results indicate that Li is most sensitive to knock-on damage at moderate electron energies, and TDE is the principal parameter for assessing Li sensitivity to knock-on damage across similar structures.
Article
Microscopy
Alexander Schroeder, Christopher Rathje, Leon van Velzen, Maurits Kelder, Sascha Schaefer
Summary: This study utilizes novel event-based electron detector platforms to extend the temporal resolution of electron microscopy. By training a neural network to predict electron arrival time, the researchers were able to improve the timing accuracy and achieve a promising solution for enhancing electron timing precision in various electron microscopy applications.
Article
Microscopy
Avi Auslender, Nivedita Pandey, Amit Kohn, Oswaldo Dieguez
Summary: This article describes a faster implementation based on DFT for computing the mean inner potential of crystals, providing quantum-mechanical calculations beyond the independent-atom approximation. The study also reveals the dependence of the mean inner potential on sample boundary conditions, mass density, and magnetic susceptibility, highlighting its correlation with various material properties.
Article
Microscopy
Zhidong Yang, Dawei Zang, Hongjia Li, Zhao Zhang, Fa Zhang, Renmin Han
Summary: In this work, we propose a self-supervised deep learning model for cryo-ET volumetric image denoising based on noise modeling and sparsity guidance. Experimental results demonstrate that our method can achieve reliable denoising by training on single noisy volume and outperform existing methods.
Article
Microscopy
J. Kuttruff, J. Holder, Y. Meng, P. Baum
Summary: In this study, a robust clustering algorithm is proposed that can find clusters in a continuous stream of raw data in real time. This algorithm converts pixel hits measured by hybrid pixel detectors to real single-electron events. By continuously comparing with previous hits, the algorithm efficiently identifies the merging of new and old events.
Article
Microscopy
D. G. Senturk, C. P. Yu, A. De Backer, S. Van Aert
Summary: This article presents a statistics-based method for accurately counting the number of atoms in nanostructures, especially for images acquired with low electron doses and multiple element structures.
Article
Microscopy
Mauricio J. Prieto, Lucas de Souza Caldas, Liviu C. Tanase, Thomas Schmidt, Oscar Rodriguez de la Fuente
Summary: This study presents a synchrotron-based investigation of the synthesis process of a magnetite/hematite bilayer. Ion bombardment gradually transforms hematite into magnetite, and the growth of magnetite leads to the formation of stable boundaries. These findings are significant for understanding novel oxide heterostructures.
Article
Microscopy
Emre Yoruk, Holger Klein, Stephanie Kodjikian
Summary: Beam sensitive nanomaterials pose challenges for crystallographic structure determination. A dose symmetric electron diffraction tomography (DS-EDT) method is developed to reduce beam damage and obtain complete data sets by merging individual datasets from multiple crystals.
Article
Microscopy
A. Pofelski, Y. Zhu, G. A. Botton
Summary: The precision and sensitivity of the GPA method for strain characterization is a widely discussed topic. This study introduces the concept of phase noise and analyzes the parameter of sampling to improve the precision of GPA. Experimental and theoretical results demonstrate that using a larger pixel spacing in STEM can enhance the precision and sensitivity of the GPA method.
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.
