Fluorescent noncovalent functionalization of graphene by surface-confined supramolecular self-assembly: towards nano-optics on graphene (Conference Presentation)

The realization of light-emitting devices based on emitters-graphene assemblies remains challenging, since graphene is known as a strong quencher of electronic excited states through excitation transfer between the adsorbed emitters and the graphene. Hence, a strategy is needed to avoid this transfer through introduction of an accurately controlled emitter–to-graphene electron barrier, for which planar flat-lying molecules are inefficient. Here, the quenching of the fluorescence of the adsorbed dye by the adjacent graphene is hindered at the molecular scale based on a spacer approach, through a specifically designed dual-functionalized self-assembling building block. This 3D tecton presents two faces, one forming a noncovalent graphene-binding pedestal and the other carrying a dye group linked by a spacer to the pedestal. The spontaneous ordering of the adsorbed layer is investigated by scanning tunneling microscopy, whereas the resulting optical properties of the whole graphene–dye hybrid system are characterized by absorption and fluorescence spectroscopies.