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MATériaux, InterfaceS, Surfaces, Environnement

High-pressure single-crystal growth of NaSi6 precursor for synthesis of (quasi) direct-bandgap silicon allotrope.

Axe 5 - Matériaux en conditions extrêmes

Thèse de Carlos Renero-Lecuna

Projet de recherche mené du 15/06/2016 au 14/12/2017

Cotutelle

Résumé

We propose to study the single-crystal growth of a new clathrate, NaSi6, a promising precursor for soft chemistry synthesis of the Si24 allotrope of silicon with zeolite structure and quasidirect bandgap. The main objective of this proposal is to obtain a single crystal of a high-pressure clathrate, to study its properties, and to transform it into the Si24 allotrope in a single crystal form. We propose to explore two types of HP experiments: (1) crystal growth in the Na-Si-Ag system and (2) direct phase transformation of cubic clathrates Na8Si46 & Na24Si136 in different pressure media. Our studies will highlight the complicated phase relationships in the Na-Si clathrate compounds, and enable us measuring bandgap and photovoltaic properties of Si24 tested up to now only on small quantities of powder samples.

13/07/18

Traductions :

    MATISSE en chiffres

    • 4 disciplines : Chimie, Physique, Sciences de la Terre, Patrimoine
    • 400 permanents

    Contact

    Direction

    Florence Babonneau

     

    Administration

    matisse @ upmc.fr

     

    Communication

    Emmanuel Sautjeau

    emmanuel.sautjeau @ sorbonne-universite.fr