Transfer of Substitutionally Implanted Graphene

Although ultralow energy (ULE) ion implantation is an effective method for substitutional doping of graphene with transition metals, it generally results in substantial nonsubstitutional incorporation, such as atoms intercalated between the graphene layer and the substrate or incorporated in the substrate subsurface. These nonsubstitutional components can have undesired or uncontrolled effects on the electronic properties of the doped graphene layer. Here, we demonstrate that graphene, substitutionally doped with Mn via ULE ion implantation, can be successfully transferred using a standard wet transfer process. This method preserves the substitutional Mn while removing the nonsubstitutional Mn present in the pretransfer surface, as evidenced by X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and scanning tunneling microscopy. Furthermore, the transferred Mn-doped graphene retains its characteristic Dirac band structure, as shown by angle-resolved photoemission spectroscopy. These results demonstrate the feasibility of transferring substitutionally doped graphene while maintaining its structural and electronic integrity. This work provides a practical route not only for studying graphene doped by ULE ion implantation using surface-sensitive techniques, free from the complications posed by nonsubstitutional components, but also for integrating it into complex structures, such as stacking with other 2D materials or transferring onto virtually any substrate or device structure.