Fig. 4: Characterization of the samples via micro-Raman spectroscopy.
From: Confinement epitaxy of large-area two-dimensional Sn at the graphene-SiC interface
a Raman spectra of the intercalated QFMLG sample, recorded for direct Sn deposited (red, A1), diffusion-driven (green, A2), and nonintercalated (blue, ZLG) areas. Insets 1, 2, and 3 show zoom-ins of the graphene G band, spatial mapping of the low-frequency Sn band, and spatial mapping of the graphene 2D band in area A1 of (b), respectively. b–g Mapping of the Raman bands of the QFMLG across the shadow mask over an 80 × 12 μm2 area. The red dashed line in (b) indicates the transition to non-intercalated ZLG, aligning with the SiC terrace direction. b D band intensity, (c) D band frequency, (d) G band intensity, (e) G band frequency, (f) 2D band intensity, and (g) 2D band frequency. h I(2D)/I(G) ratio for the areas A1 and A2, relating lateral doping profiles. i Strain and doping correlation in A1 and A2. The inset shows strain (ϵ, blue) and doping (n, orange) lines. The data in (a–i) were acquired using 532 nm laser excitation. j) Dispersions with excitation energy: frequencies (black) and width (blue) for the QFMLG/Sn (squares) measured in A1 and MLG (circles). The nonintercalated ZLG areas are masked in (b–h) for proper evaluation.
