Tip-enhanced Raman spectroscopy: principles and applications

Abstract

This review provides a detailed overview of the state of the art in tip-enhanced Raman spectroscopy (TERS) and focuses on its applications at the horizon including those in materials science, chemical science and biological science. The capabilities and potential of TERS are demonstrated by summarising major achievements of TERS applications in disparate fields of scientific research. Finally, an outlook has been given on future development of the technique and the mechanisms of achieving high signal enhancement and spatial resolution.

Tip‐enhanced Raman spectroscopy (TERS) on double perovskite La2CoMnO6 thin films: field enhancement and depolarization effects

“…Hence, in the parallel scattering, only the non‐depolarized field enhancement component of the near‐field takes effect. This is in good agreement with results on crystalline silicon and GaAs, where also a strong polarization dependence of the contrast and a tip‐induced near‐field depolarization were observed.…”

“…Because the spatial resolution for Raman spectroscopy is diffraction limited in the visible range to approximately ~200 nm and the cross section for Raman scattering (~10 −30 cm 2 ) is about 14–16 magnitudes lower than that of fluorescence (~10 −14 –10 −16 cm 2 ), a weak intensity and a low resolution are the key problems for nanoscaled samples. To overcome these challenges, tip‐enhanced Raman spectroscopy (TERS) uses an apertureless noble metal tip from an atomic force microscope (AFM) or a scanning tunneling microscope (STM) as a hot spot probe . The intensity enhancement is induced locally by an extra near‐field generation around the noble metal tip apex due to surface plasmon polariton (SPP) excitation on its metal surface, a lightning rod effect at the tip end and antenna resonances .…”

Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

“…Due to the larger energetic distance of PL emission relative to excitation and the limited energetic width of the LSP, we expect the amplification of  to be less strong than the enhancement of the Raman emission, leading to the PL probing deeper into the film than the Raman tip-enhanced measurement (see more details in Supplementary Note 1). The lateral resolution is similar for both tip-enhanced Raman and PL maps, typically being < 25 nm, which is about ten times better than the diffraction-limited lateral resolution (200 -300 nm) of a confocal optical microscope 23 . is too weak to be observed in the optical spectrum.…”

“…21 . In addition to investigating OPV polymerfullerene blends 22 , TEOS has been used to probe nanoscale chemical composition in a wide range of research areas such as catalysis, semiconductors, biology, graphene and single molecule detection 23 .…”

Shell‐Isolated Nanoparticle‐Enhanced Raman Spectroscopy at Single‐Crystal Electrode Surfaces

“…Interestingly, TERS technique merges Raman spectroscopy with scanning probe microscopy (SPM) to provide chemical information with high spatial information. [ 69 ] When the tip is positioned at the centre of a laser focus, the electromagnetic fi eld is signifi cantly enhanced due to a combination of localized surface plasmon resonance (LSPR) and lightning rod effect. [ 69 ] When the tip is positioned at the centre of a laser focus, the electromagnetic fi eld is signifi cantly enhanced due to a combination of localized surface plasmon resonance (LSPR) and lightning rod effect.…”