Near-Infrared optoelectronic devices with atomically controlled graphene nanostructures
The extraordinary and ultrafast electro-optical response of graphene nanostructures has enabled order-unity changes in absorption due to the switching on and off of plasmons via electrical gating, thus suggesting application to ultrafast light modulation. Unfortunately, graphene plasmons have so far been observed at mid-infrared and longer wavelengths, therefore limiting their use as optoelectronic devices in the visible and near-infrared (vis-NIR) spectral range. Reaching this energy regime requires an efficient doping of graphene by confining the lateral dimension below 5 nm, which is beyond the state-of-art top-down lithography resolution. Alternatively, this project will use a bottom-up chemical route recently developed by the host organization to synthesize atomically precise, 1nm wide, graphene nanoribbons (GNRs) that can couple laterally to give rise to either nanoporous graphene structures or laterally interconnected GNRs arrays, for efficient gate-doping. The project aims to explore the feasibility of fabricating optoelectronic devices based on the plasmonic properties of atomically precise graphene nanostructures. The nature of the project is highly multidisciplinary, involving a combination of well-developed chemistry, physics, electronics and photonics that will focus at three different levels: chemical synthesis of atomic-size GNRs and characterization, nanostructure transfer and device fabrication, and electro-optical characterization. This proposal promotes both the transfer of knowledge to the host institution and the training of the candidate in new advanced techniques. The proof-of-concept of such device will pave the way for ultra-high speed photodetectors that are capable of handling record data transmission at vis-NIR range, thus providing key solutions for next generation data communications. This project lines up perfectly with the EU strategy, “Graphene Flagship”, in fostering the emergence of foundational breakthroughs in graphene science.