Publications associées à Polaron hopping through piecewise-linear functionals

Nonempirical semilocal density functionals for correcting the self-interaction of polaronic states

Through the use of the piecewise-linearity condition of the total energy, we correct the self-interaction for the study of polarons by constructing nonempirical functionals at the semilocal level of theory. We consider two functionals, the gamma DFT and mu ...

Aip Publishing2024

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

Drift-Diffusion Simulations of Charge Transport and Trap Dynamics in Organic Semiconductor Materials

Camilla Arietta Vael-Garn

Polymeric semiconductors have gained significant attention in the field of organic electronics due to their unique properties and potential applications. Through their ability to transport charge carriers and to absorb or emit light, they have attracted mu ...

EPFL2023

Hubbard U through polaronic defect states

Alfredo Pasquarello, Stefano Falletta

Since the preliminary work of Anisimov and co-workers, the Hubbard corrected DFT+U functional has been used for predicting properties of correlated materials by applying on-site effective Coulomb interactions to specific orbitals. However, the determinatio ...

NATURE PORTFOLIO2022

Polarons free from many-body self-interaction in density functional theory

Alfredo Pasquarello, Stefano Falletta

We develop a unified theoretical framework encompassing one-body and many-body forms of self-interaction. We find an analytic expression for both the one-body and the many-body self-interaction energies, and quantitatively connect the two expressions throu ...

2022

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

Etienne Christophe Socie

Over the past decade, lead halide perovskites (LHPs) have received considerable attention thanks to their impressive optoelectronic properties. Today, LHP-based devices are one of the most efficient single-junction solar cells, with power-conversion effici ...

EPFL2022

Interaction of Confined Polaritons in Microcavity Structures

Morteza Navadeh Toupchi

A polariton is a quasiparticle formed from the coupling of a confined photon in a cavity to electronic excitation, like exciton in a semiconductor. This dissertation reports on series of experiments in confined polariton interaction by design, fabrication, ...

EPFL2021

Time- and Angle-Resolved Photoelectron Spectroscopy of Solar Materials

Serhii Polishchuk

Natural foundations defining the manner in which a solid material interacts with optical radiation are primarily encoded in the material's momentum-dependent band structure and the microscopic details of the electron-lattice interactions. An access to this ...

EPFL2021

Direct measurement of key exciton properties: Energy, dynamics, and spatial distribution of the wave function

Martin Wolf, Michele Puppin

Excitons, Coulomb-bound electron-hole pairs, are the fundamental excitations governing the optoelectronic properties of semiconductors. Although optical signatures of excitons have been studied extensively, experimental access to the excitonic wave functio ...

Wiley2021

Computational Modeling of the Oxygen Evolution Reaction at Semiconductor-Water Interfaces: A Path Towards Breaking Linear Scaling Relationships

Patrick Gono

Photoelectrochemical water splitting is a promising source of clean, renewable fuel in the form of hydrogen. Despite extensive research endeavors, the widespread adoption of this technology is impeded due to suboptimal catalysts for the oxygen evolution re ...

EPFL2020

Evidence of Large Polarons in Photoemission Band Mapping of the Perovskite Semiconductor CsPbBr3

Marco Grioni, Majed Chergui, Alberto Crepaldi, Nicola Marzari, Nicola Colonna, Gianmarco Gatti, Serhii Polishchuk, Thomas Roland Barillot, Michele Puppin, Riccardo De Gennaro, Matthias Wolf

Lead-halide perovskite (LHP) semiconductors are emergent optoelectronic materials with outstanding transport properties which are not yet fully understood. We find signatures of large polaron formation in the electronic structure of the inorganic LHP CsPbB ...

AMER PHYSICAL SOC2020

Small Electron Polarons in CsPbBr3: Competition between Electron Localization and Delocalization

Alfredo Pasquarello, Julia Anna Wiktor, Stefano Falletta

We study the nature of excess electrons in CsPbBr3 and identify several single and double polaronic states. We emphasize the importance of proper inclusion of the self-interaction corrections for the stability of small electron polarons in this material. W ...

AMER CHEMICAL SOC2020

Terahertz surface modes and electron-phonon coupling on Bi2Se3(111)

Davide Campi

We present a combined experimental and theoretical study of the surface vibrational modes of the topological insulator Bi2Se3 with particular emphasis on the low-energy region below 10 meV that has been difficult to resolve experimentally. By applying inel ...

AMER PHYSICAL SOC2020

Exciton and Carrier Dynamics in Two-Dimensional Perovskites

Jacques-Edouard Moser, Marine Eva Fedora Bouduban, Etienne Christophe Socie, Andrés Burgos Caminal

Two-dimensional Ruddlesden−Popper hybrid lead halide perovskites have become a major topic in perovskite optoelectronics. Here, we aim to unravel the ultrafast dynamics governing the evolution of charge carriers and excitons in these materials. Using a com ...

2020

Electron and Hole Polarons at the BiVO4-Water Interface

Alfredo Pasquarello, Julia Anna Wiktor

We determine the transition levels of electron and hole polarons at the BiVO4-water interface through thermodynamic integration within a hybrid functional scheme, thereby accounting for the liquid nature of the water component. The electron polaron is foun ...

2019

Nonequilibrium exciton physics in hybrid lead-halide perovskites and anatase titanium dioxide

Tania Palmieri

The strength of the electron-hole interaction in bulk semiconductors is not only determined by the dielectric environment, but also depends on the presence of other quasiparticles - free charge carriers or phonons - that populate the system. In the former ...

EPFL2019

Enhanced Electron-Phonon Interaction in Multivalley Materials

Helmuth Berger, Nicola Marzari, Evgeniy Ponomarev, Marco Gibertini, Thibault Daniel Pierre Sohier

We report a combined experimental and theoretical investigation that reveals a new mechanism responsible for the enhancement of electron-phonon coupling in doped semiconductors in which multiple inequivalent valleys are simultaneously populated. Using Rama ...

American Physical Society2019

Excitonic effects in two-dimensional TiSe2 from hybrid density functional theory

Oleg Yazyev, Diego José Pasquier

Transition metal dichalcogenides (TMDs), whether in bulk or in monolayer form, exhibit a rich variety of charge-density-wave (CDW) phases and stronger periodic lattice distortions. While the actual role of nesting has been under debate, it is well understo ...

AMER PHYSICAL SOC2018

Long-lived Photo-Charges in 1D Helical Organic Semiconductor Nanostructures

Regina Judith Hafner

The formation of photoexcited states in organic semiconductors, their separation into long-lived or stable charge carriers, as well as the charge transport are critical processes relevant to several important research fields and emerging technologies. Whil ...

EPFL2018

Unusually Long-Lived Photocharges in Helical Organic Semiconductor Nanostructures

Andrzej Sienkiewicz, Jürgen Brugger, Jan Cornelius Brauer, Valentin Flauraud, Holger Frauenrath, Liangfei Tian, Regina Judith Hafner, Thomas Schmaltz

Photocharge generation and formation of long-lived charge carriers are relevant in photosynthesis, photocatalysis, photovoltaics, and organic electronics. A better understanding of the factors that determine these processes in synthetic polymer semiconduct ...

AMER CHEMICAL SOC2018