Publications associées à Finite-size corrections of defect energy levels involving ionic polarization

Automated all-functionals infrared and Raman spectra

Infrared and Raman spectroscopies are ubiquitous techniques employed in many experimental laboratories, thanks to their fast and non-destructive nature able to capture materials' features as spectroscopic fingerprints. Nevertheless, these measurements freq ...

Nature Portfolio2024

Hydrogen-induced tunable remanent polarization in a perovskite nickelate

Michele Kotiuga

Materials with field-tunable polarization are of broad interest to condensed matter sciences and solid-state device technologies. Here, using hydrogen (H) donor doping, we modify the room temperature metallic phase of a perovskite nickelate NdNiO3 into an ...

Nature Portfolio2024

Instabilities in Elastic and Magneto-Elastic Beams and Shells: from Shell Buckling to the Design of a Programmable Braille Reader

Arefeh Abbasi

In this thesis, we conduct a comprehensive investigation into structural instabilities of both elastic and magneto-elastic beams and shells, resulting in a creative proposal to design a programmable braille reader. Methodologically, we combine numerical si ...

EPFL2024

On the Validity of Consensus

Rachid Guerraoui, Seth Gilbert, Manuel José Ribeiro Vidigueira, Jovan Komatovic, Pierre Philippe Civit

The Byzantine consensus problem involves.. processes, out of which t < n could be faulty and behave arbitrarily. Three properties characterize consensus: (1) termination, requiring correct (nonfaulty) processes to eventually reach a decision, (2) agreement ...

Assoc Computing Machinery2023

From defect to effect: controlling electronic transport in chevron graphene nanoribbons

Oleg Yazyev, Kristians Cernevics

While bottom-up synthesis allows for precise control over the properties of graphene nanoribbons (GNRs), the use of certain precursor molecules can result in edge defects, such as missing benzene rings that resemble a 'bite'. We investigate the adverse eff ...

IOP Publishing Ltd2023

Machine-learning the electronic density of states: electronic properties without quantum mechanics

Chiheb Ben Mahmoud

The electronic density of states (DOS) quantifies the distribution of the energy levels that can be occupied by electrons in a quasiparticle picture and is central to modern electronic structure theory. It also underpins the computation and interpretation ...

EPFL2023

Self-Interaction and Polarons in Density Functional Theory

Stefano Falletta

The electron self-interaction is a long-standing problem in density functional theory and is particularly critical in the description of polarons. Polarons are quasiparticles involving charge localization coupled with self-induced lattice distortions. Sinc ...

EPFL2023

Thermal Conditions in Indoor Environments: Exploring the Reasoning behind Standard-Based Recommendations

Dolaana Khovalyg

Professionals in the building design and operation fields typically look at standards and guidelines as a reliable source of information and guidance with regard to procedural, contractual, and legal scope and requirements that are relevant to accountabili ...

2023

koopmans: An Open-Source Package for Accurately and Efficiently Predicting Spectral Properties with Koopmans Functionals

Nicola Marzari, Giovanni Borghi, Ngoc Linh Nguyen, Nicola Colonna, Riccardo De Gennaro, Edward Baxter Linscott, Andrea Ferretti

Over the past decade we have developed Koopmans functionals, a computationally efficient approach for predicting spectral properties with an orbital-density-dependent functional framework. These functionals impose a generalized piecewise linearity conditio ...

Amer Chemical Soc2023

Foldable Hole-Transporting Materials for Merging Electronic States between Defective and Perfect Perovskite Sites

Keith Gregory Brooks, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Kasparas Rakstys, Yi Zhang, Hiroyuki Kanda, Ruiyuan Hu, Jianxing Xia, Qurat Ul Ain

Defective and perfect sites naturally exist within electronic semiconductors, and considerable efforts to reduce defects to improve the performance of electronic devices, especially in hybrid organic-inorganic perovskites (ABX(3)), are undertaken. Herein, ...

Wiley-V C H Verlag Gmbh2023

Berry curvature dipole generation and helicity-to-spin conversion at symmetry-mismatched heterointerfaces

Peng Chen, Xupeng Yang

The Berry curvature dipole (BCD) is a key parameter that describes the geometric nature of energy bands in solids. It defines the dipole-like distribution of Berry curvature in the band structure and plays a key role in emergent nonlinear phenomena. The th ...

Nature Portfolio2023

Nonlinear electro-mechanical coupling and thermally stimulated currents in relaxor ferroelectrics

Lukas Riemer

In this work, the emergence of polarization and electro-mechanical coupling in Pb(Mg1/3Nb2/3)O3 and Pb(Mg1/3Nb2/3)O3 â PbTiO3 was investigated by means of thermally stimulated current, and nonlinear dielectric and electro-mechanical measurements. The pre ...

EPFL2022

Stoichiometry modulates the optoelectronic functionality of Zinc Phosphide (Zn3-xP2+x)

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Maria Chiara Spadaro, Simon Robert Escobar Steinvall, Santhanu Panikar Ramanandan, Rajrupa Paul, Diego Armando Sandoval Salaiza, Mirjana Dimitrievska, Mischa Samuel Flór

Predictive synthesis–structure–property relationships are at the core of materials design for novel applications. In this regard, correlations between the compositional stoichiometry variations and functional properties are essential for enhancing the perf ...

2022

Stress effects on the impedance and ferroelectricity of PVDF-BiFeO3-MWCNT films using xanthan gum as dispersant

Frank Nüesch, Francis Owusu

Composite films based on dispersions of bismuth ferrite (BiFeO3) in polyvinylidene fluoride (PVDF) matrixes were prepared in the presence of multiwalled-carbon-nanotubes (MWCNT), using xanthan gum (XG) as dispersant. Films were prepared by spin coating and ...

ELSEVIER SCIENCE SA2022

Accurate and efficient band-gap predictions for metal halide perovskites at finite temperature

Alfredo Pasquarello, Patrick Gono, Thomas Bischoff, Aleksei Tal, Haiyuan Wang

We develop a computationally efficient scheme to accurately determine finite-temperature band gaps for metal halide perovskites belonging to the class ABX(3) (A = Rb, Cs; B = Ge, Sn, Pb; and X = F, Cl, Br, I). First, an initial estimate of the band gap is ...

NATURE PORTFOLIO2022

Nanoscale Growth Initiation as a Pathway to Improve the Earth-Abundant Absorber Zinc Phosphide

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Growth approaches that limit the interface area between layers to nanoscale regions are emerging as a promising pathway to limit the interface defect formation due to mismatching lattice parameters or thermal expansion coefficient. Interfacial defect mitig ...

AMER CHEMICAL SOC2022

High Permittivity Siloxanes as Promising Materials for Dielectric Elastomer Transducers: From Synthesis to Application

Yauhen Sheima

The speed of change in the modern world is impressive. Within the last 50 years, many devices and technologies have significantly transformed their appearance, intrinsic characteristics and improved their performance. Computers have changed from the size o ...

EPFL2022

Field-induced ultrafast modulation of Rashba coupling at room temperature in ferroelectric alpha-GeTe(111)

Jan Hugo Dil

Rashba materials have appeared as an ideal playground for spin-to-charge conversion in prototype spintronics devices. Among them, alpha-GeTe(111) is a non-centrosymmetric ferroelectric semiconductor for which a strong spin-orbit interaction gives rise to g ...

Nature Portfolio2022

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

Jean-François Carlin, Nicolas Grandjean, Mauro Mosca, Camille Haller

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Effects of surface rigidity and metallicity on dielectric properties and ion interactions at aqueous hydrophobic interfaces

Philip Robin Loche

Using classical molecular dynamics simulations, we investigate the dielectric properties at interfaces of water with graphene, graphite, hexane, and water vapor. For graphite, we compare metallic and nonmetallic versions. At the vapor-liquid water and hexa ...

AIP Publishing2022