A5089524803- Electrochemical Analysis and Applications
- 2D Materials and Applications
- Electrocatalysts for Energy Conversion
- Advanced battery technologies research
- MXene and MAX Phase Materials
- Machine Learning in Materials Science
- Perovskite Materials and Applications
- Graphene research and applications
- Boron Compounds in Chemistry
- Chalcogenide Semiconductor Thin Films
- Thermodynamic and Structural Properties of Metals and Alloys
- Semiconductor materials and devices
- Thermal properties of materials
- Advanced Memory and Neural Computing
- Quantum and electron transport phenomena
- Quantum Information and Cryptography
- Parallel Computing and Optimization Techniques
- Alcoholism and Thiamine Deficiency
- Mechanical and Optical Resonators
- Vitamin C and Antioxidants Research
- Advanced Data Storage Technologies
- Electrochemical sensors and biosensors
- Conducting polymers and applications
- Cyclopropane Reaction Mechanisms
- Molecular Junctions and Nanostructures
Aalto University
2017-2025
Two-dimensional (2D) sheets of transition metal phosphorus trichalcogenides (TMPTs) offer unique magnetic and optical properties that can complement those found in other 2D materials. Insights into the structure these materials be obtained by a juxtaposition experimental calculated Raman spectra, but there is very little theoretical knowledge vibrational TMPTs. Using first-principles calculations, we study mechanical large set monolayer From phonon dispersion curves, assess dynamical...
Thermal properties of molybdenum disulfide (MoS$_2$) have recently attracted attention related to fundamentals heat propagation in strongly anisotropic materials, and the context potential applications optoelectronics thermoelectrics. Multiple empirical potentials been developed for classical molecular dynamics (MD) simulations this material, but it has unclear which provides most realistic results. Here, we calculate lattice thermal conductivity single- multi-layer pristine MoS$_2$ by...
Abstract Successful application of two-dimensional transition metal dichalcogenides in optoelectronic, catalytic, or sensing devices heavily relies on the materials’ quality, that is, thickness uniformity, presence grain boundaries, and types concentrations point defects. Raman spectroscopy is a powerful nondestructive tool to probe these factors but interpretation spectra, especially separation different contributions, not straightforward. Comparison simulated spectra beneficial, for...
Abstract In this work, we study ultra-low energy implantation into MoS 2 monolayers to evaluate the potential of technique in two-dimensional materials technology. We use 80 Se + ions at 20 eV and with fluences up 5.0·10 14 cm −2 . Raman spectra implanted films show that are predominantly incorporated sulfur sites 2−2 x alloys formed, indicating high ion retention rates, agreement predictions molecular dynamics simulations irradiation on monolayers. found rate is improved when performed an...
The efficient integration of transition metal dichalcogenides (TMDs) into the current electronic device technology requires mastering techniques effective tuning their optoelectronic properties. Specifically, controllable doping is essential. For conventional bulk semiconductors, ion implantation most developed method offering stable and tunable doping. In this work, we demonstrate n-type in MoSe2 flakes realized by low-energy Cl+ ions followed millisecond-range flash lamp annealing (FLA)....
Abstract High‐order force constant expansions can provide accurate representations of the potential energy surface relevant to vibrational motion. They be efficiently parametrized using quantum mechanical calculations and subsequently sampled at a fraction cost underlying reference calculations. Here, are combined via hiphive package with GPU‐accelerated molecular dynamics simulations GPUMD obtain an accurate, transferable, efficient approach for sampling dynamical properties materials. The...
The kinetic rates of electrochemical reactions depend on electrodes and molecules in question. In a flow battery, where the electrolyte are charged discharged electrodes, efficiency electron transfer is crucial importance for performance device. purpose this work to present systematic atomic-level computational protocol studying between electrode. computations done by using constrained density functional theory (CDFT) ensure that either electrode or electrolyte. ab initio molecular dynamics...
The water solubility of organic molecules is critical for optimizing the performance and stability aqueous flow batteries, as well various other applications. Although relatively straightforward to measure in some cases, theoretical prediction remains a considerable challenge. To this end, machine learning algorithms have become increasingly important tools past decade. High-quality data effective descriptors are essential constructing reliable data-driven estimation models. We...
The integration of charged polymers and reverse osmosis membranes presents a promising approach to capture undesired ions enhance water purification efficiency. In this paper, di-block cationic polyacrylamides (DCPAMs) as are evaluated separately in bulk solution within process nitrite introduced by NaNO3. To achieve this, molecular dynamics simulations conducted systematically investigate the effects polymer configuration, concentration, salt concentration on ion adsorption performance....
Silicon carbide is a very promising platform for quantum applications because of extraordinary spin and optical properties point defects in this technologically-friendly material. These are strongly influenced by crystal vibrations, but the exact relationship between them behavior qubits not fully investigated. We uncover local vibrational modes Si vacancy as-grown 4H-SiC. apply resonant microwave field to isolate contribution from one particular type defects, so-called V2 center, observe...
We combine experimental and theoretical methods to understand the impact of long-range Coulomb interactions on phonons excitons in ZrS<sub>x</sub>Se<sub>2−x</sub>.
Silicon carbide with optically and magnetically active point defects offers unique opportunities for quantum technology applications. Since interaction these commonly happens through optical excitation de-excitation, a complete understanding of their light-matter in general signatures, particular, is crucial. Here, we employ mechanical density functional theory calculations to investigate the photoluminescence lineshapes selected, experimentally observed color centers (including single...
Herein we report the successful doping of tellurium (Te) into molybdenum disulfide (MoS2) monolayers to form MoS2x Te2(1-x) alloy with variable compositions via a hydrogen-assisted post-growth chemical vapor deposition process. It is confirmed that H2 plays an indispensable role in Te substitution as-grown MoS2 monolayers. Atomic-resolution transmission electron microscopy allows us determine lattice sites and concentration introduced atoms. At relatively low concentration, only substituted...
Proton-electron transfer (PET) reactions are rather common in chemistry and crucial energy storage applications. How electrons protons involved or which mechanism dominates is strongly molecule pH dependent. Quantum chemical methods can be used to assess redox potential (Ered.) acidity constant (pKa) values but the computations time consuming. In this work, supervised machine learning (ML) models predict PET analyze molecular space. The data for ML have been created by density functional...
We have examined the utility of pyridoxal hydrochloride, a vitamin B6 vitamer and biobased feedstock, as starting point towards organic redox flow battery materials. Pyridoxal hydrochloride was synthetically converted to series diverse B6-based redox-active benzoyl pyridinium salts. These compounds were electrochemically characterized through cyclic voltammetry (CV) measurements in neutral basic aqueous electrolytes (1 M KCl 0.1 NaOH). Based on CV results, which demonstrated reversibility...
We propose an electromechanical scheme where the electronic degrees of freedom boron vacancy color centers hosted by a hexagonal nitride nanoribbon are coupled for quantum information processing. The mutual coupling is provided via their to mechanical motion ribbon, which in turn stems from local strain. strengths computed performing ab-initio calculations. density functional theory (DFT) results on monolayers reveal huge strain susceptibility. In our analysis, we take into account effect...
Raman spectroscopy is a widely used, powerful, and nondestructive tool for studying the vibrational properties of bulk low-dimensional materials. spectra can be simulated using first-principles methods but due to high computational cost calculations are usually limited only fairly small unit cells, which makes it difficult carry out simulations alloys defects. Here, we develop an efficient method simulating alloys, benchmark against full density-functional theory calculations, apply several...
The features of some potential single-photon sources in two-dimensional silicon carbide monolayers is studied via ab-initio calculation and group theory analysis. A few point defects three charge states (negative, positive neutral) are considered. By applying performance criteria, Stone-Wales without with combination antisite details. formation energy calculations reveal that neutral these stable. We compute the zero-phonon-line energy, Huang-Rhys (HR) factor photoluminescence spectrum for...
Diazo compounds are commonly employed as carbene precursors in transfer reactions during a variety of functionalization procedures. Release N2 gas from diazo may lead to formation, and the ease this process is highly dependent on characteristics substituents located vicinity moiety. A quantum mechanical density functional theory assisted by machine learning was used investigate relationship between chemical features activation energy required for elimination. Our results suggest that...
Pyridoxal hydrochloride, a vitamin B
Mechanistic redox and acid-base reactions play pivotal roles in numerous applications both chemistry biology. Bridging the gap between computational insights experimental observations is crucial to illuminate mechanisms underlying these processes. In this study, we enhanced our understanding of electrochemical by leveraging scheme squares framework using a set tens molecules that have been examined field flow batteries. Furthermore, focused on developing models calibrating calculated...
For many materials, Raman spectra are intricately structured and provide valuable information about compositional stoichiometry crystal quality. Here we use density-functional theory calculations, mass approximation, the intensity weighted $\Gamma$-point density of state approach to analyze scattering vibrational modes in zincblende, wurtzite, hexagonal BX (X = N, P, As) structures. The influence structure boron isotope disorder on line shapes is examined. Our results demonstrate that...
The kinetic rates of electrochemical reactions depend on electrodes and molecules in question. In a flow battery, where the electrolyte are charged discharged electrodes, efficiency electron transfer is crucial importance for performance device. purpose this work to present systematic atomic-level computational protocol studying between electrode. computations done by using constrained density functional theory (CDFT) ensure that either electrode or electrolyte. ab-initio molecular dynamics...