Noble metal nanoparticle / graphene hybrid systems exhibit promising functionality for implementation in electronic, optoelectronic and SERS devices. Here, a detailed analysis of the structural, optical, and transport properties of Ag/graphene system after sequential Ag nanoparticle (Ag NP, D~5nm) deposition on graphene by sputtering is reported. Insight into the evolution of the physical properties of these graphene­based materials will provide valuable tools to understand and tailor the functionality of these hybrid materials. Results reveal two different regimes in their optical and electric performance, depending on graphene coverage with Ag NPs. Optical transmittance spectra reveal that full coverage (at a deposition time ~60s) sets a significant increase of the plasmon intensity with increasing Ag NPs deposition time. This concomitantly yields an abrupt enhancement of the graphene Raman signal, determining the SERS performance of Ag NPs/graphene­based devices. On the other hand, the evolution of the transport properties reveals an increase of the sheet resistance of graphene with Ag NP incorporation below the full coverage regime accompanied by a progressive n­doping. These results are consistent with the charged­impurity scattering model at this regime. However, above the full coverage point, no significant variation of resistivity or density of carriers is observed, suggesting that subsequent Ag NPs deposition does not modify the electric performance of graphene.

Oral presentation given at the 2015 E-MRS Spring Meeting, held in Lille (France) from May 11 to 15, 2015. Materials for Advanced Electronics. Symposium Y: Science and technology of two-dimensional materials.