Electric Field-Induced Nano-Assembly Formation: First Evidence of Silicon Superclusters with a Giant Permanent Dipole Moment

• Published in: Nanomaterials (Basel, Switzerland) Vol. 13; no. 15; p. 2169
• Main Authors: Jardali, Fatme, Tran, Jacqueline, Liège, Frédéric, Florea, Ileana, Leulmi, Mohamed E, Vach, Holger
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26-07-2023; MDPI
• Subjects: Absorption spectra; Analysis; Atomic force microscopy; Atoms & subatomic particles; Clusters; Condensed Matter; Density functionals; Dipole moments; Electric dipoles; Electric fields; Electrodes; Engineering Sciences; hydrogenated silicon nanoclusters; Hydrogenation; Identification and classification; Materials Science; Microscopy; Nanoclusters; Nanoparticles; permanent electric dipole moment; Phase transitions; Physics; Plasma; Plasmas; Properties; self-assembled nanostructures; Silicon; Superclusters; surface deposition; Transmission electron microscopy; France; superclusters; hydrogenated silicon nanoclusters; self-assembled nanostructures; permanent electric dipole moment; surface deposition
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano13152169

The outstanding properties of silicon nanoparticles have been extensively investigated during the last few decades. Experimental evidence and applications of their theoretically predicted permanent electric dipole moment, however, have only been reported for silicon nanoclusters (SiNCs) for a size of about one to two nanometers. Here, we have explored the question of whether suitable plasma conditions could lead to much larger silicon clusters with significantly stronger permanent electric dipole moments. A pulsed plasma approach was used for SiNC production and surface deposition. The absorption spectra of the deposited SiNCs were recorded using enhanced darkfield hyperspectral microscopy and compared to time-dependent DFT calculations. Atomic force microscopy and transmission electron microscopy observations completed our study, showing that one-to-two-nanometer SiNCs can, indeed, be used to assemble much larger "superclusters" with a size of tens of nanometers. These superclusters possess extremely high permanent electric dipole moments that can be exploited to orient and guide these clusters with external electric fields, opening the path to the controlled architecture of silicon nanostructures.