https://doi.org/10.1051/epjap/2022210276
Regular Article
Visualizing the effects of plasma-generated H atoms in situ in a transmission electron microscope★
1
LPICM, École polytechnique, IP Paris, CNRS UMR7647, 91120 Palaiseau, France
2
LSI, École polytechnique, IP Paris, CEA-DRF-IRAMIS, CNRS UMR7642, 91120 Palaiseau, France
* e-mail: jean-luc.maurice@polytechnique.edu
Received:
6
December
2021
Accepted:
3
January
2022
Published online: 4 February 2022
The radicals and atoms generated by a plasma have the effect, among others, of changing the surface energies of materials, which allows one to prepare nano-objects that would not stabilise in other conditions. This is the case of the Sn catalysed silicon nanowires (NWs) we present in this paper: without plasma, the liquid Sn at the top of NWs is unstable (because Sn naturally wets the Si) so that no growth is allowed, while in presence of the H atoms generated by the plasma, the balance of surface energies is drastically changed; the Sn droplet stabilises and can be used efficiently by the vapour-liquid-solid (VLS) mechanism of growth. Thus, if one wants to study the growth mechanisms of such NWs in situ in the transmission electron microscope (TEM), one has to adapt a plasma system on the TEM. This is precisely what was done at École polytechnique on the NanoMAX environmental TEM. The paper reports on the plasma effects, on the catalyst and on NW growth, recorded in situ in real time, at atomic resolution. The results are discussed in the light of density functional calculations of bare and hydrogenated Si surface energies.
Supplementary material is available in electronic form at https://www.epjap.org/10.1051/epjap/2022210276
© J.-L. Maurice et al., Published by EDP Sciences, 2022
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
