Electrical Transport in Atomically Precise Graphene Nanoribbon Transistors with Transferred Electrodes

Graphene nanoribbons (GNRs), atomically precise strips of graphene, exhibit tunable bandgaps dependent on the ribbon width that can exceed 3 eV. This unique property, coupled with their high carrier mobility and excellent thermal conductivity, positions them as superior candidates for both conventional and wide-bandgap semiconductor applications, offering the potential for devices with higher performance, lower power consumption, and improved thermal management.

However, realizing the full potential of GNRs has been hindered by challenges such as contact resistance and degradation of the GNRs due to the device fabrication process. This work demonstrates a novel fabrication approach for GNR field-effect transistors that aims to minimize GNR damage and enhance device performance.

In this work, we fabricated field-effect transistors using nine-atom-wide armchair GNRs (9-AGNRs) synthesized on Au(111)/mica substrates; where they were transferred onto the dielectric SiO2/Si device substrate using a wet transfer method. Pd, Sb, or Graphene contacts were fabricated on separate SiO2/Si substrates using electron beam lithography and physical vapor deposition. These contacts were subsequently transferred onto the GNR substrate using a PMMA polymer transfer technique. The Electronic properties for these devices are compared with traditionally fabricated devices using a state-of-the-art probe station to measure key device metrics such as on-state current, on/off current ratio, and subthreshold swing.