Defects and domain boundaries in self-assembled terephthalic acid (TPA) monolayers on CVD-grown graphene on Pt(111).

Self-assembly of terephthalic acid (TPA), vacuum deposited on Pt(111) supported graphene, has been investigated by scanning tunneling microscopy (STM). TPA organizes in an ordered 3 × 4 superstructure with respect to the graphene lattice. This structure is a consequence of hydrogen-bonded TPA chains that arrange in a commensurate overlayer on graphene. Due to the polycrystalline nature of graphene on Pt(111), the TPA layer exhibits various grain boundaries and dislocations. Molecular resolved STM imaging has been used to characterize these defect structures in the TPA monolayer.