A periodically modulated graphene (PMG) generated by nanopatterned surfaces is reported to profoundly modify the intrinsic electronic properties of graphene. The temperature dependence of the sheet resistivity and gate response measurements clearly show a semiconductor-like behavior. Raman spectroscopy reveals significant shifts of the G and the 2D modes induced by the interaction with the underlying grid-like nanostructure. The influence of the periodic, alternating contact with the substrate surface was studied in terms of strain caused by bending of graphene and doping through chemical interactions with underlying substrate atoms. Electronic structure calculations performed on a model of PMG reveals that it is possible to tune a band gap within 0.14-0.19 eV by considering both the periodic mechanical bending and the surface coordination chemistry. Therefore, the PMG can be regarded as a further step toward band gap engineering of graphene devices.

We report Raman analysis of few-layer graphene (FLG) transferred on flat and patterned substrate structures. These different surface structures created by patterning an area of a Si-substrate produce differences in the interaction between FLG and the substrate surface. The topography measurement performed by scanning tunneling potentiometry shows that the FLG on the patterned substrate was deformed periodically with 3-4 nm depth variation. Raman spectroscopy reveals that two important features related to the G-and 2D-modes in graphitic structures show different sensitivity to the interaction with the substrate for single-layer graphene (SLG), FLG, and graphite. Whereas SLG and FLG placed on the patterned substrate demonstrate a strong shift of both 2D-and G-peaks to lower frequencies with respect to the flat part, the multilayer graphene in a graphite flake shows almost no difference between patterned and non-patterned substrates. We identified the origin of the observed changes in the Raman spectra of SLG and FLG as effects created by the underlying substrate. Especially, substrate induced periodic strain and surface interaction were taken into account to interpret the results.