477 citations · 4.6k across the 66 of their papers we have counts for
68 papers
Revealing the free energy landscape of halide perovskites: Metastability and transition characters in CsPbBr and MAPbI
Erik Fransson, J. Magnus Rahm, Julia Wiktor +1
Halide perovskites have emerged as a promising class of materials for photovoltaic applications. A challenge in these applications is how to prevent the crystal structure from degr…
Small-angle scattering tensor tomography algorithm for robust reconstruction of complex textures
Leonard C. Nielsen, Paul Erhart, Manuel Guizar-Sicairos +1
The development of small-angle scattering tensor tomography has enabled the study of anisotropic nanostructures in a volume-resolved manner. It is of great value to have reconstruc…
Quantifying Dynamic Tilting in Halide Perovskites: Chemical Trends and Local Correlations
Julia Wiktor, Erik Fransson, Dominik Kubicki +1
Halide perovskites have emerged as one of the most interesting materials for optoelectronic applications due to their favorable properties, such as defect-tolerance and long charge…
Tuning the lattice thermal conductivity in van-der-Waals structures through rotational (dis)ordering
Fredrik Eriksson, Erik Fransson, Christopher Linderälv +2
It has recently been demonstrated that MoS2 with irregular interlayer rotations can achieve an extreme anisotropy in the lattice thermal conductivity (LTC), which is for example of…
Phase transitions in inorganic halide perovskites from machine learning potentials
Erik Fransson, Julia Wiktor, Paul Erhart
The atomic scale dynamics of halide perovskites have a direct impact not only on their thermal stability but their optoelectronic properties. Progress in machine learned potentials…
Limits of the phonon quasi-particle picture at the cubic-to-tetragonal phase transition in halide perovskites
Erik Fransson, Petter Rosander, Fredrik Eriksson +3
The soft modes associated with continuous-order phase transitions are associated with strong anharmonicity. This leads to the overdamped limit where the phonon quasi-particle pictu…
GPUMD: A package for constructing accurate machine-learned potentials and performing highly efficient atomistic simulations
Zheyong Fan, Yanzhou Wang, Penghua Ying +17
We present our latest advancements of machine-learned potentials (MLPs) based on the neuroevolution potential (NEP) framework introduced in [Fan et al., Phys. Rev. B 104, 104309 (2…
Hot-carrier transfer across a nanoparticle-molecule junction: The importance of orbital hybridization and level alignment
Jakub Fojt, Tuomas P Rossi, Paul Erhart
While direct hot-carrier transfer can increase photo-catalytic activity, it is difficult to discern experimentally and competes with several other mechanisms. To shed light on thes…
The moiré potential in twisted transition metal dichalcogenide bilayers
Christopher Linderälv, Joakim Hagel, Samuel Brem +2
Moiré superlattices serve as a playground for emerging phenomena, such as localization of band states, superconductivity, and localization of excitons. These superlattices are larg…
High-throughput characterization of transition metal dichalcogenide alloys: Thermodynamic stability and electronic band alignment
Christopher Linderälv, J. Magnus Rahm, Paul Erhart
Alloying offers a way to tune many of the properties of the transition metal dichalcogenide (TMD) monolayers. While these systems in many cases have been thoroughly investigated pr…
Computational Design of Alloy Nanostructures for Optical Sensing of Hydrogen
Pernilla Ekborg-Tanner, J. Magnus Rahm, Victor Rosendal +4
Pd nanoalloys show great potential as hysteresis-free, reliable hydrogen sensors. Here, a multi-scale modeling approach is employed to determine optimal conditions for optical hydr…
Quantitative predictions of thermodynamic hysteresis: Temperature-dependent character of the phase transition in Pd-H
J. Magnus Rahm, Joakim Löfgren, Paul Erhart
The thermodynamics of phase transitions between phases that are size-mismatched but coherent differs from conventional stress-free thermodynamics. Most notably, in open systems suc…
Exciton landscape in van der Waals heterostructures
Joakim Hagel, Samuel Brem, Christopher Linderälv +2
van der Waals heterostructures consisting of vertically stacked transition-metal dichalcogenides (TMDs) exhibit a rich landscape of bright and dark intra- and interlayer excitons.…
A tale of two phase diagrams: Interplay of ordering and hydrogen uptake in Pd-Au-H
J. Magnus Rahm, Joakim Löfgren, Erik Fransson +1
Due to their ability to reversibly absorb/desorb hydrogen without hysteresis, Pd--Au nanoalloys have been proposed as materials for hydrogen sensing. For sensing, it is important t…
Dipolar coupling of nanoparticle-molecule assemblies: An efficient approach for studying strong coupling
Jakub Fojt, Tuomas P. Rossi, Tomasz J. Antosiewicz +2
Strong light-matter interactions facilitate not only emerging applications in quantum and non-linear optics but also modifications of materials properties. In particular the latter…
Photoluminescence Lineshapes for Color Centers in Silicon Carbide from Density Functional Theory Calculations
Arsalan Hashemi, Christopher Linderalv, Arkady V. Krasheninnikov +3
Silicon carbide with optically and magnetically active point defects offers unique opportunities for quantum technology applications. Since interaction with these defects commonly…
DYNASOR -- A tool for extracting dynamical structure factors and current correlation functions from molecular dynamics simulations
Erik Fransson, Mattias Slabanja, Paul Erhart +1
Perturbative treatments of the lattice dynamics are widely successful for many crystalline materials, their applicability is, however, limited for strongly anharmonic systems, meta…
Tunable Phases of Moiré Excitons in van der Waals Heterostructures
Samuel Brem, Christopher Linderälv, Paul Erhart +1
Stacking monolayers of transition metal dichalcogenides into a heterostructure with a finite twist-angle gives rise to artificial moiré superlattices with a tunable periodicity. As…
Luminescence quenching via deep defect states: A recombination pathway via oxygen vacancies in Ce-doped YAG
Christopher Linderälv, Daniel Åberg, Paul Erhart
Luminescence quenching via non-radiative recombination channels limits the efficiency of optical materials such as phosphors and scintillators and therefore has implications for co…
Vibrational signatures for the identification of single-photon emitters in hexagonal boron nitride
Christopher Linderälv, Witlef Wieczorek, Paul Erhart
Color centers in h-BN are among the brightest emission centers known yet the origins of these emission centers are not well understood. Here, using first-principles calculations in…
A Computational Assessment of the Efficacy of Halides as Shape-Directing Agents in Nanoparticle Growth
Joakim Löfgren, J. Magnus Rahm, Joakim Brorsson +1
We report a comprehensive study of aqueous halide adsorption on nanoparticles of gold and palladium that addresses several limitations hampering the use of atomistic modeling as a…
Local vibrational modes of Si vacancy spin qubits in SiC
Z. Shang, A. Hashemi, Y. Berencén +4
Silicon carbide is a very promising platform for quantum applications because of extraordinary spin and optical properties of point defects in this technologically-friendly materia…
Hot-Carrier Generation in Plasmonic Nanoparticles: The Importance of Atomic Structure
Tuomas P. Rossi, Paul Erhart, Mikael Kuisma
Metal nanoparticles are attractive for plasmon-enhanced generation of hot carriers, which may be harnessed in photochemical reactions. In this work, we analyze the coherent femtose…
Defects from phonons: Atomic transport by concerted motion in simple crystalline metals
Erik Fransson, Paul Erhart
Point defects play a crucial role in crystalline materials as they do not only impact the thermodynamic properties but are also central to kinetic processes. While they are necessa…