Substrate enhanced infrared nanospectroscopy of molecular vibrations
CIC nanoGUNE Seminars
- Speaker
-
Lars Mester
- When
-
2019/09/09
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
-
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S-SNOM and nano-FTIR spectroscopy allow for label-free mapping and chemical
identification of organic and inorganic materials with nanoscale spatial
resolution. However, the detection of thin molecular layers and nanostructures
on standard substrates is still challenged by weak signals.
Here, we demonstrate a significant enhancement of nano-FTIR signals of a thin
organic layer by exploiting polariton-resonant tip-substrate coupling and
surface polariton illumination of the probing tip. We achieve up to nearly one
order of magnitude signal enhancement on a phonon-polaritonic quartz (c-SiO2)
substrate, as compared to nano-FTIR spectra obtained on metal (Au) substrates,
and up to two orders of magnitude when compared to the standard infrared
spectroscopy substrate CaF2. Our results will be of critical importance for
boosting nano-FTIR spectroscopy towards the routine detection of monolayers
and single molecules.