Tip-enhanced resonance Raman spectroscopy (TERRS) has been demonstrated by a research team at Fritz-Haber Institute. The results suggest that TERRS could offer a new approach for the atomic-scale optical characterization of local electronic states.
The researchers demonstrated TERRS on ultrathin zinc oxide layers epitaxially grown on a Ag(111) surface in which both physical and chemical enhancement mechanisms were operative. The underlying process was examined by modifying the localized surface plasmon resonance in a scanning tunneling microscope junction and recording different-thickness zinc oxide films that exhibited a slightly different electronic structure.
In combination with scanning tunneling spectroscopy (STS), the research team demonstrated that the TERRS intensity was dependent on the local electronic resonance of the zinc oxide/Ag(111) interface. The team also showed that the spatial resolution of TERRS was dependent on the tip-surface distance and could reach nearly 1 nm in the tunneling regime.