Laboratoire de Physique des Interfaces et des Couches Minces

CNRS - École polytechnique - Institut Polytechnique de Paris

In-situ ETEM Studies of Fe Catalyst NPs Formation under Molecular or Radicals/Activated Hydrogen Environments for the Growth of SWCNTs

Contributors: Ileana Florea (LPICM), Mariam Ezzedine (LPICM), Mihai-Robert Zamfir (LPICM), Loan Truong (LPICM), Eleonor Caristan (LPICM) and Costel – Sorin Cojocaru (LPICM) The present study is focused on the realization of in situ TEM observations of Fe catalyst film dewetting and catalytic nanoparticles (NPs) formation under molecular and/or radical/ activated hydrogen environments. The formed NPs […]

In-situ TEM SWCNTs growth observation under gas environment and under electric field

The goal of the project is to study the influence of the electric fields on the growth of free-standing carbon nanotubes(CNTs) by chemical vapor deposition (CVD) used in field emission (FE) applications. The growths are performed in an environmental transmission electron microscope (ETEM) with the ETEM growths observed in real-time under  C2H2 environment at 700° […]

Understanding the generation of silicide nanowires by CVD in situ in a TEM

Metallic nanowires (NWs) may be of interest in many nano-electronics or plasmonics applications. Nanowires based on silicon are of particular interest as they are naturally compatible with Si technology. Among the latter, nickel silicide NWs are very conductive and could replace copper connections or transparent conductive oxides.1 Regarding fundamental materials science, their growth occurs in […]

Understanding the generation of polytypism in semiconductor nanowires through in situ observations in a TEM

The VLS (vapour-liquid-solid) and VSS (vapour-solid-solid) modes of semiconductor nanowire (NW) growth present the possibility of naturally delivering metastable crystal polytypes directly, without any additional treatment [1,2]. The mechanisms, for that natural occurrence of out-of-equilibrium structures, are fairly well understood for compound semiconductors [3,4]. However, if such polytypes sometimes also appear in elemental  semiconductor nanowires, like in […]

Visualizing the effects of plasma-generated H atoms in-situ in the NanoMAX transmission electron microscope

In plasma-enhanced chemical vapour deposition (PECVD), reactive species generated by the plasma have the effect, among others, of changing the surface energies of the growing materials, which allows one to prepare objects that would not stabilize otherwise. Here, we use this property to stabilize Sn droplets used as catalysts in the growth of Si nanowires […]

Insight into the formation and stability of solid electrolyte interphase (SEI) for nanostructured silicon-based anode electrodes used in Li-ion batteries

Silicon-based anode fabrication with nano-scale structuration improves the energy density and life cycle of Li-ion batteries. As-synthesized silicon (Si) nanowires (NWs) or nanoparticles (NPs) directly on the current collector represent a credible alternative to conventional graphite anode. However, the operating potentials of these electrodes are below the electrochemical stability window of all electrolytes used in […]