Raman modes and mapping of graphene nanoparticles on Si and photonic crystal substrates

Abstract

Mapping of photonic crystal (PC) surface infiltrated by graphene nanoparticles (GNP) has been done for D, G, and 2D mode and compared with those for GNP deposited on Si substrate. We've collected numerous spectra (from about 1000 points) and the changes in D, G, and 2D modes intensity ratio, as well as minor changes in frequency position for both GNP samples, have been detected. The samples were extremely heterogeneous in spectroscopic features. A suppression of luminescence intensity from the opal-based PC after the infiltration of GNP into interglobular cavities of the PC was registered together with up to 3–10 times enhancement of the Raman signal from the GNP which is important for the development of enhanced spectroscopic techniques. Thus, graphene showed a property of suppression of luminescence from the PC similar to a metallic substrate and could be applied as a luminescence quencher and light absorber. These data are confirmed by finite-difference time-domain (FDTD) calculations.

Keywords

• Graphene nanoparticles
• Photonic crystal
• Raman modes mapping
• Raman enhancement
• Luminescence suppression