Category Archives: research

Concours : Directeur de recherche au CNRS

Cette année, j’ai enfin réussi le concours de directeur de recherche du CNRS en section 3, après six tentatives.Dans cet article, je souhaite partager les différents projets de recherche et présentations que j’ai utilisés au fil des années, en espérant qu’ils puissent être utiles à d’autres candidats. Presentations: Electronic and optical properties of nano-materials (2023)… Read More

Electrical monitoring of organic crystal phase transition using MoS2 field effect transistor

Hybrid van der Waals heterostructures made of 2D materials and organic molecules exploit the high sensitivity of 2D materials to all interfacial modifications and the inherent versatility of the organic compounds. In this study, we are interested in the quinoidal zwitterion/MoS2 hybrid system in which organic crystals are grown by epitaxy on the MoS2 surface… Read More

Luminescence in hexagonal boron nitride single layer: exciton-phonon coupling and the role of substrate

In this new work we study luminescence in monolayer hexagonal boron nitride (m-hBN) using a new ab-initio approach that takes into account the effects of atomic vibrations on the luminescence spectra. We construct the dynamical exciton-phonon self-energy, then use it to perturbatively correct the optical response functions and test this approach on bulk hBN as… Read More

A squashed and squeezed h-BN

In this seminar I present new thoeretical and exparimental results on hexagonal-boron nitride under isotropic pressure and uni-axial strain. In particalar we focused on the changes in the optical response both absortion and emission. We show how exicton behave under these extreme conditions.The presentation can You can downloaded here: A squashed and squeezed h-BN [ODP]

On-surface chemistry using local high electric fields

On-surface chemistry is a promising topic in nanoscience and is widely applied for the generation of a multitude of nanostructures and to the local chemical modification of adsorbed molecules in order to tune their properties or create layers with new functionalities. Using an electric field to control chemical reactions is a concept that has been… Read More

Yambo school 2020: new video lectures and tutorials are online

The “Computational School on Electronic Excitations in Novel Materials Using the Yambo Code” school at the ICTP has just ended. In this school we presented an introduction to many-body theory, a new version of the code that include all the non-linear response part. The new tutorials that are available in the wiki webpage. Moreover all… Read More

Computational School on Electronic Excitations in Novel Materials Using the Yambo Code

The Computational School on Electronic Excitations in Novel Materials Using the Yambo Code, introduces participants to post-DFT simulations, in particular many-body perturbation theory (MBPT) approaches and provide training in the calculation of electronic and optical properties of materials. The program will offer theoretical and technical lectures, as well as dedicated hands-on sessions where the students… Read More

The story of Academic Publishing: from Galileo to Nature

I was invited to give a seminar at the conference of young Italian researchers. At this conference I will present a  talk on the story of academic publishing. I will briflely present the story of academic publising, from the first journals to the modern publication system, passing through open access, impact factor, etc… I show… Read More

Theory of phonon-assisted luminescence

In this presentation I present the theory of phonon-assisted luminescence, in terms of non-equilibrium  Green’s functions and time-dependent perturbation theory. We derived a simple formule for light emission in the limit of low excited carriers including excitonic effects and then included coupling with phonons by time-dependent perturbation theory. This approach is then applied to the… Read More

Luminescence of hexagonal boron nitride explained

Luminescence of hexagonal boron nitride (hBN) has puzzled researchers for long time. In standard solid state physics textbooks direct band gap semiconductors are considered efficient light emitters while indirect ones are regarded as inefficient. Hexagonal boron nitride seems to defy this rule. In fact hBN emits light in the ultraviolet with an efficient comparable to… Read More