This Debye lunch lecture, Electronic components embedded in a single graphene nanoribbon, will be given by Peter Jacobse from the Condensed Matter & Interfaces research group.
Use of graphene in electronic devices requires opening a band gap in its band structure, which can be achieved by creating nanostructures such as graphene nanoribbons (GNRs). Recently, on-surface synthesis has resulted in the possibility to create nanoribbons with atomic precision. For future applications, we can integrate the contacts and more functionality directly into single ribbons by using GNR heterostructures. We have used this approach to fabricate metal-semiconductor junctions and tunnel barriers in single GNR consisting of 5-atom wide and 7-atom wide segments with atomically precise interfaces. We characterized the atomic scale geometry and electronic structure by combined atomic force microscopy (AFM), scanning tunneling microscopy (STM). In addition, we have performed conductance measurements by lifting nanoribbons off the surface with the tip of a STM and characterized them after transfer onto sodium chloride monolayers, which acts as an electronic decoupling agent in these experiments. These junctions are extremely relevant for developing contacts in all-GNR devices, creating diodes and transistors and act as a first step towards complete electronic devices built into a single GNR.