Self-assembly of silicon nanowires studied by advanced transmission electron microscopy.
Scanning transmission electron microscopy (STEM) was successfully applied to the analysis of silicon nanowires (SiNWs) that were self-assembled during an inductively coupled plasma (ICP) process. The ICP-synthesized SiNWs were found to present a Si-SiO2core-shell structure and length varying from ≈100 nm to 2-3 μm. The shorter SiNWs (maximum length ≈300 nm) were generally found to possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor-liquid-solid (VLS) mechanism within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up approaches used for the production of thin SiNWs.
Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, Catania 95123, Italy; CNR IMM-MATIS, Via S. Sofia 64, Catania 95123, Italy; Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada.
Marta
M
Agati
CNR IMM-MATIS, Via S. Sofia 64, Catania 95123, Italy; Institut Pprime, UPR 3346, CNRS - Université de Poitiers, ISAE-ENSMA, 11 Boulevard Marie et Pierre Curie, 86962 Futuroscope-Chasseneuil, France.
Guillaume
G
Amiard
Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada.
Vincent Le
VL
Borgne
Dipartimento di Fisica, Università di Roma "Tor Vergata", Via della Ricerca Scientifica 1, Roma 00133, Italy.
Paola
P
Castrucci
Tekna Plasma Systems Inc., 2935 Industrial Blvd., Sherbrooke QC-J1L 2T9, Canada.
Richard
R
Dolbec
Dipartimento di Fisica, Università di Roma "Tor Vergata", Via della Ricerca Scientifica 1, Roma 00133, Italy.
Maurizio
M
De Crescenzi
Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada.
My Alì
MA
El Khakani
CNR IMM-MATIS, Via S. Sofia 64, Catania 95123, Italy.
Simona
S
Boninelli
silicon nanowires; transmission electron microscopy; vapor–liquid–solid growth