Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Bienvenue sur le site de l'AFC

Intitulé du poste : PhD Offer - Monte-Carlo simulations of the growth of 2D silicene and germanene
Ville : Paris
Laboratoire/Institut : Institut des Nanosciences de Paris
Description du poste : Description: 2D-materials are promising candidates for both fundamental science and electronic and photonic2D-materials are promising candidates for both fundamental science and electronic and photonicapplications. After the development of graphene, a significant interest is devoted to silicene andgermanene due both to their exotic properties, presence of a band-gap and potential easy integration indevices. The production of these 2D layers by molecular beam epitaxy is under extensive investigationto improve the quality and sizes that are limited in the classical exfoliation techniques. The need for abetter control of the growth procedure is clear and requires understanding of the growth mechanisms.Different substrates have been explored to host these layers, from metals to hBN, graphene, transitionmetal dicalcogenides etc. In particular, dedicated experiments have been performed in the hostinggroup on the growth of Si and Ge on metallic substrates, see Fig. 1, revealing the importance ofalloying [1]. However, the way to control the morphologies and properties of the resulting layersremains unknown. It requires both new modelization tools to describe the growth of such systems,together with a strong coupling between theory and experiments to tackle the physics at work.The best numerical tool to investigate the growth dynamicsis kinetic Monte-Carlo simulations (KMC) [2]. Thanks to anumber of controlled approximations, they can efficientlydescribe the dynamics of realistic atomistic models on largescalesystems (from hundreds of nanometers up tomicrometers) and on experimental growth time-scale (fromminutes up to hours). By assuming a lattice-dynamics, thesesimulations have been first developed to accurately describethe growth of submonolayer deposition and have beenextended to describe epitaxial growth more generally [3].These models can be implemented to account for therelevant microscopic effects (covalent binding, wettingeffects, alloying, elasticity, etc).

Thesis work: The goal of this thesis is twofold. First, the PhD student will develop a KMC framework for thesimulation of the growth of silicene and germanene layers on different substrates, Ag(111), Al(110)etc. The student will implement a KMC code that will include the mechanisms relevant in experiments: interaction with the substrate, geometry, alloying, exchange etc. This work will take benefit from theresults of experimental investigations, that will feed the modelization with microscopic parameters,but also of first-principles calculations. Of special interest will be the account of alloying that wasprecisely revealed on Ag in the hosting group. A systematic analysis of the resulting model will bedone in order to shed new light on the experimental growth modes. Second, the PhD student will alsoparticipate to dedicated experimental runs for the growth and characterization of silicene andgermanene layers. Overall, this work is expected to reveal the mechanisms that trigger the growth of2D silicene and germanene, and to guide experimental procedures to produce new materials.
[1] Curcella A., Bernard R., Borensztein Y., Lazzeri M., Resta A., Garreau Y., Prévot G., 2D Materials 4(2017) 025067
[2] Curcella A., Bernard R., Borensztein Y., Pandolfi S., Prévot G., Bellstein J. Nanotechnol. 9 (2018) 48
[3] Gaillard P., Aqua J.-N., Frisch, T., Physical Review B 87 (2013) 125310
Durée du contrat : 3 ans
Date de prise de fonction : 01-10-2020
Personne à contacter : Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser., (http://www.insp.jussieu.fr/-Aqua-Jean-Noel-.html)Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser. , http://www.insp.jussieu.fr/-Prevot-Geoffroy-
Téléphone : -
Email : Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser., Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser.