FePc Adsorption on the Moir\'e Superstructure of Graphene Intercalated with a Co Layer

TL;DR

This study combines density functional theory and spectroscopic techniques to analyze FePc molecule adsorption on a graphene moiré superstructure intercalated with Co, revealing how local electronic properties are influenced by the substrate's corrugation.

Contribution

It provides a detailed theoretical and experimental analysis of FePc adsorption on a graphene/Co system, highlighting the role of substrate corrugation in molecular interaction.

Findings

Adsorption regions are controlled by the distance of C atoms from Co.

Local electronic properties vary within the corrugated interface.

Interaction strength depends mainly on the C-Co distance.

Abstract

The moir\'e superstructure of graphene grown on metals can drive the assembly of molecular architectures, as iron-phthalocyanine (FePc) molecules, allowing for the production of artificial molecular configurations. A detailed analysis of the Gr/Co interaction upon intercalation (including a modelling of the resulting moir\'e pattern) is performed here by density functional theory, which provides an accurate description of the template as a function of the corrugation parameters. The theoretical results are a preliminary step to describe the interaction process of the FePc molecules adsorption on the Gr/Co system. Core level photoemission and absorption spectroscopies have been employed to control the preferential adsorption regions of the FePc on the graphene moir\'e superstructure and the interaction of the central Fe ion with the underlying Co. Our results show that upon molecular adsorption the distance of C atoms from the Co template mainly drives the strength of the molecules-substrate interaction, thereby allowing for locally different electronic properties within the corrugated interface.