Creating a good contact between electrodes and graphene nanoribbons (GNRs) has been a longstanding challenge in searching for the next GNR-based nanoelectronics. This quest requires the controlled fabrication of sub-20 nm metallic gaps, a clean GNR transfer minimizing damage and organic contamination during the device fabrication, as well as work function matching to minimize the contact resistance. Here, we transfer 9-atom-wide armchair-edged GNRs (9-AGNRs) grown on Au(111)/mica substrates to pre-patterned platinum electrodes, yielding polymer-free 9-AGNR field-effect transistor devices. Our devices have a resistance in the range of 106 to 108Ω in the low-bias regime, which is 2 to 4 orders of magnitude lower than previous reports. Density functional theory (DFT) calculations combined with the non-equilibrium Green's function method (NEGF) explain the observed p-type electrical characteristics and further demonstrate that platinum gives strong coupling and higher transmission in comparison to other materials such as graphene.
@article{arxiv.2301.13814,
title = {Platinum contacts for 9-atom-wide armchair graphene nanoribbons},
author = {Chunwei Hsu and Michael Rohde and Gabriela Borin Barin and Guido Gandus and Daniele Passerone and Mathieu Luisier and Pascal Ruffieux and Roman Fasel and Herre S. J. van der Zant and Maria El Abbassi},
journal= {arXiv preprint arXiv:2301.13814},
year = {2023}
}