cfaed Seminar Series

Naresh Kumar , National Physical Laboratory, UK

Visualising surface chemistry beyond diffraction limit using tip-enhanced Raman spectroscopy

14.02.2017 (Tuesday) , 15:30 - 17:00
TU Chemnitz, Institute of Physics, Room P032 , Reichenhainerstr. 70 , 09126 Chemnitz

143 years ago Ernst Abbe discovered that it is impossible to resolve surface features having size below the diffraction limit using an optical microscopes. Today, we have a range of analytical techniques that have successfully overcome the diffraction barrier allowing visualisation of surface chemistry and molecular phenomenon with a nanoscale resolution. In this talk, I would introduce a powerful super-resolution imaging technique called tip-enhanced Raman spectroscopy (TERS) in which the diffraction limit is overcome using light interaction with metal nanostructures, AKA plasmonics. TERS involves a combination of Raman spectroscopy with Scanning Probe Microscopy (SPM), enabling simultaneous mapping of surface chemical composition and topography at the nanoscale. I would demonstrate the application of this powerful technique with three case studies:

  1. Mapping of heterogeneous catalytic reactions at the nanoscale1
  2. Visualisation and characterisation of nanoscale defects in Graphene and 2D materials2-4
  3. Simultaneous topography, electrical and optical microscopy of optoelectronic devices at the nanoscale5

Finally, I would discuss the metrology challenges of this emerging technique and the recent progress made in TERS metrology at NPL

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