Local work function on graphene nanoribbons

Area of Science:

• Materials Science
• Surface Science
• Condensed Matter Physics

Background:

• Graphene nanoribbons exhibit unique electronic properties influenced by charge carriers, confinement, and atomic structure.
• Local work function variations indicate surface heterogeneity, crucial for understanding material behavior.

Purpose of the Study:

• To map the local contact potential difference (LCPD) of graphene nanoribbons grown on a Au(111) substrate.
• To investigate charge transfer and doping effects at the graphene-gold interface.
• To correlate atomic structure with electronic properties at the nanoscale.

Main Methods:

• Utilizing Kelvin probe force microscopy (KPFM) to measure LCPD.
• Growing graphene nanoribbons on a Au(111) substrate.
• Performing density functional theory (DFT) calculations for corroboration.

Main Results:

• KPFM successfully mapped LCPD variations across graphene nanoribbons.
• Evidence of significant charge transfer between graphene nanoribbons and the gold substrate was observed.
• DFT calculations confirmed that LCPD variations reflect nanoribbon doping.

Conclusions:

• The study demonstrates KPFM's capability to probe electronic variations in graphene nanoribbons.
• Charge transfer and doping are key factors influencing the electronic properties of graphene nanoribbons on gold.
• Understanding these structure-property relationships is vital for designing graphene-based electronic devices.