Surface-enhanced raman spectroscopy on ultrathin gold/graphene substrates near the percolation threshold.

In this work, we carried out a complex analysis of gold films near the percolation threshold. It was determined how graphene influences the growth of films and which benefits it provides to the substrates for their application in SERS. Gold films were deposited on two types of substrates by electron-beam evaporation and the thickness of these films ranged from 3 to 10 nm. The first type of substrate was silicon with a thin layer of silicon oxide and the second type was the same substrate, with a single layer CVD graphene. The characterization of films was carried out using such experimental methods as scanning electron microscope (SEM), atomic force microscope (AFM), ellipsometry and sheet resistance measurements. SERS measurements of the dye Crystal Violet showed sufficiently large enhancement factor (EF) and also graphene induced photoluminescence quenching was demonstrated. [ABSTRACT FROM AUTHOR]