Fig. 1: Device diagrams of a graphene-Ru-DAE-graphene single-molecule FET.
From: Dual-gated single-molecule field-effect transistors beyond Moore’s law
a Schematic representation of the device structure. Bottom: Atomic force microscopic image of nanogapped graphene point contacts with the bottom gate. Top: Schematic of the device center that highlights the reversible isomerisation of the DAE unit between ring-open and ring-closed forms that are triggered by optical stimuli. b Optical images of a graphene-Ru-DAE-graphene single-molecule FET array with a common bottom gate based on a HfO2/Al2O3/Al multilayer. The inset shows the complete pattern, where the central region marked by a red circle is enlarged for clarity. c Left: Cross-sectional scanning transmission electron microscope (STEM) image of the HfO2/Al2O3/Al multilayer structure. The sample was prepared using a focused ion beam and imaged using the STEM (200 kV). Right: Analyses of the elemental compositions of the dielectric layer, which includes hafnium, oxygen, and aluminum, performed using an energy-dispersive X-ray spectroscopy system. These characterizations show that the thickness of both the Al2O3 and HfO2 layers is ~5 nm.
