Charge transport and light-matter interactions go hand-in-hand and are important in areas of science ranging from biology, green energy and energy storage, catalysis, chemistry, physics, to nano-electronics and modern day data processing. In the context of the latter, one of the key challenges is to interface optics with nanoscale electronics. In my group we have been studying the mechanisms of charge transport and light-matter interactions in nanoscale tunnelling junctions were quantum effects dominate. Molecular tunnelling junctions are appealing as, in principle, they allow to study the mechanisms of charge transport at the molecular length-scales, provide endless opportunities via chemical modification, and organic molecules or organic thin films have interesting non-linear optical properties that can be vastly different from their bulk counter parts. To make an impact on society, it is crucial to identify new paradigms that can be integrated with current day or future technologies. Keeping this in mind, it is important to also explore junctions based on, for example, novel metal oxides, 2D materials, and non-linear organic thin films. To achieve these goals, it is crucial to develop new versatile platforms that allow to study the mechanisms of charge transport and light matter interactions across a great variety of (molecular) structures at the nanoscale.