C60 molecules grown on a Si-supported nanoporous supramolecular network: a DFT study

Area of Science:

• Surface Science
• Materials Chemistry
• Computational Chemistry

Background:

• Fullerene assemblies exhibit unique electronic properties, but forming ordered arrays on silicon is difficult due to competing interactions.
• Achieving controlled C60 fullerene deposition on surfaces is crucial for advanced electronic applications.

Purpose of the Study:

• To investigate the deposition of C60 fullerene molecules on a 1,3,5-tri(1'-bromophenyl)benzene (TBB) monolayer on a Si(111)-boron (SiB) surface.
• To understand the positioning and stabilization mechanisms of C60 molecules within the TBB network.
• To explore the potential for creating stable 3D supramolecular networks.

Main Methods:

• Density functional theory (DFT) simulations were employed to model C60 fullerene adsorption.
• Calculations of adsorption energy were performed to determine molecular positioning and stability.
• Analysis of charge density differences was used to understand bonding interactions.

Main Results:

• C60 molecules are precisely positioned in nanopores formed by the TBB network on the SiB surface.
• The SiB surface controls the vertical position, while the TBB network dictates the lateral position and stability of C60.
• No covalent bonds are formed, but significant charge reorganization occurs between C60, Si adatoms, and TBB molecules.
• A stable C60 array sandwiched between two TBB layers was predicted, paving the way for 3D network growth.

Conclusions:

• A TBB monolayer on SiB effectively controls C60 fullerene assembly, overcoming challenges in ordered array formation.
• The van der Waals interactions and charge reorganization facilitate stable C60 positioning and potential for 3D supramolecular structures.
• This approach offers a pathway for fabricating novel fullerene-based materials with tailored electronic properties.