Influence of tip geometry on the spatial resolution of tip enhanced Raman mapping

Zhang Chao¹, Chen Bao-Qin², Li Zhi-Yuan^{1, †,}

The local field intensities for different tip apex radii obtained under the conventional theory ((a), (c), (e), (g) for R = 10 nm, 20 nm, 30 nm, 40 nm) and the modified theory considering the molecular self-interaction ((b), (d), (f), (h) for R = 10 nm, 20 nm, 30 nm, 40 nm). The molecule (polarizability β = 5β₀) locates at r_z = 1 nm, r_x = 0 nm (blue mark) and the tip–substrate distance is d = 2 nm.