Molecular junctions represent a fascinating frontier in the realm of nanotechnology and are one of the
smallest optoelectronic devices possible, consisting of individual molecules or a group of molecules
that serve as the active element sandwiched between conducting electrodes. As devices approach
the molecular scale, quantum mechanical effects become dominant, leading to a host of novel
properties that do not exist in larger-scale devices. This thesis delves into electrically integrated and
plasmonically enhanced molecular junctions, which are instrumental in understanding interactions
at the metal-molecule interfaces. These junctions combine the optical capabilities of high field
confinement (and enhancement) and high radiative efficiency, with the electrical capabilities of
molecular transport. They can probe the electronic structure and dynamics of the molecules within
the junction, offering a view of the electronic transitions, molecular vibrations, conformational
changes in the molecules, charge transfer, and quantum transport properties. Their potential in
pioneering nanoscale optoelectronic applications, such as ultrafast electronics and nanosensing, is
significant. However, the complexity involved in creating scalable and robust molecular junctions at
ambient operating conditions poses a substantial challenge. In this thesis, we present the utilization
of a self-assembled molecular junction equipped with a nanoparticle bridge to explore the correlated
fluctuations in conductance and the light emission induced by inelastic electron tunneling at room
temperature. Unlike large-area SAM junctions, both the electrical conductance and light emission are
remarkably sensitive to atomic-scale fluctuations, even though hundreds of molecules are present in
the junction. This phenomenon mirrors the behavior observed in picocavities in Raman scattering
and the luminescence blinking seen in photo-excited plasmonic junctions. Moving localization of
these point-like emitters (identified as the movement of gold atoms at the surface) is observed in the
light emission spectra and is supported by the conductance data. The research conducted for this
thesis demonstrates a scalable molecular junction platform that facilitates both optical and electrical
interrogation at the atomic level.