Abstract:
Plasmonic nanostructures give major insights into the interaction between light and matter
at nanoscale. Also, they have potential practical applications in various elds such as in
biosensing(sensing of di erent types of molecules, proteins), plasmonic circuits, as metama-
terials. The realization of their practical application is possible only when one understands
their properties entirely. Therefore, in this thesis, we study the technique to understand
localized surface plasmon resonance(LSPR) properties. Also, we have made an attempt to
probe the plasmon-exciton coupling. Therefore this thesis is divided into two parts.
In the rst part, we have studied a technique which can collect single particle spectra
called dark eld spectroscopy. The setup is based on Total Internal Re
ection of light.
The study is majorly focused on scattering due to sub-wavelength structures. Gold nanos-
tars prepared by us was probed by dark eld scattering technique. We have discussed the
information that we can extract from the spectra obtained.
The next part is focused on coupling of plasmonic nanostructure with two-dimensional
material Molybdenum disul de MoS2 which is an excitonic material. 2-D material MoS2 has
tremendous applications in the eld of optoelectronics because of their direct bandgap nature
because of which it shows Photoluminescence. Our system comprises of silver nanowires on
few layers of MoS2. In our experiments, we have compared the Photoluminescence emission
from MoS2 and that from wire on MoS2, both its magnitude and directionality. Our results
show that silver nanowire on MoS2 shows nanoantenna e ect. Taking this study forward
can give major insights about coupling of excitons and plasmons, also the results themselves
have implications in nanophotonic circuits.
