We explore the fascinating properties of modern solid state nanosystems with a current focus on 2D systems and van der Waals hetero- and hybridstructures. Our aim is to gain fundamental understanding of such systems, and to learn in a subsequent step to control and tailor their properties on purpose with the vision to achieve novel functionalities and at the same time to look for potential applications in an interdisciplinary context. Therefore the nanosystems are integrated in proof-of-concept and prototypical devices to explore their potential for opto-/electronic, solar energy harvesting and catalytic applications, and to serve as test-bed structures towards quantum technologies at the same time.