In this study, we introduce a new method to enhance the Raman signals of a graphene-Rhodamine 6G (R6G)-graphene sandwich structure by creating a magnet-induced static pressure to maximize the chemical contact between the R6G molecules and graphene. The increase in pressure in the graphene-R6G-graphene sandwich geometry plays a crucial role in enhancing the Raman signal by approximately up to 30 times in comparison to that acquired from a R6G/graphene layered film. In addition, the pressure-induced enhancement effects in the planar vibrational motion of the R6G (1200-1500 cm-1) were more recognizable than those in the low-wavenumber region and were almost comparable to the surface-induced enhancement effects in the Raman scattering signals observed from the spontaneously formed 'folded' pseudo-π-bonded graphene-R6G-graphene sandwich structures. The enhancement effect diminished with an increase in the number of graphene layers (on the bottom side), which was clearly discernible when graphene/glass sandwiched structures placed on top of exfoliated multilayered graphene coated with R6G were imaged.
Bibliographical noteFunding Information:
H.K. acknowledges the provision of the basic research programs (14-NB-04) and a start-up fund for new researchers through the Daegu Gyeongbuk Institute of Science and Technology (DGIST) funded by the Ministry of Science , ICT , and Future Planning of Korea . J.-H.A. acknowledges the Research Program (CASE-2014M3A6A5060933 and 2009-0083540) through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT, and Future Planning of Korea.
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All Science Journal Classification (ASJC) codes
- Materials Science(all)