Optoelectronic devices are at the core of today’s information revolution, bridging digital electronics and optical fibre communications. As the global internet traffic increases with a higher rate than the capacities of optical networks, new miniaturised optoelectronic technologies integrated on silicon could prove to be a powerful solution. The EU-funded SubNanoOptoDevices project paved the way to a new technology for optoelectronic components based on low-dimensional materials to achieve increased data rates and reduced power consumption. It explored a radically new way to engineer the electrical and optical properties of these materials (specifically 2D materials and van der Waals heterostructures) to achieve, for instance, optical modulators with tunable wavelengths and unprecedented modulation speeds. In conclusion, the project succesfully developed a fabrication method that can implement in a top down way structures in the order of a few nanometers in size (which can be easily extended to less than one nanometer) and proved new theoretical and experimental nanophotonic devices. It also led to the creation of a new type of finite difference numerical software with improved performances to simulate quantum mechanical and optical phenomena.