Doping single-layer graphene with aromatic molecules

A study was conducted to demonstrate the preparation of single-layer graphene (SLG) films through mechanical exploitation of highly oriented pyrolytic graphite (HOPG) and modify them with various aromatic molecules. It was found that the molecules bound to SLG films through strong π-π interactions between their aromatic rings and the graphene. Electrical measurements on SLG-based field-effect transistors revealed that the aromatic molecules with electron-donating groups caused n-doping, while those with electron-withdrawing groups imposed p-doping on the SLG. The doping effect by these aromatic molecules were characterized by Raman spectroscopy. Itv was suggested that the charge impurity or ripping on the SLG film had the potential to cause an inhomogeneous charge distribution that led to variations of Raman features.