Probing the electronic structure of a nanopatterned graphene device using nanoARPES

The lithographic patterning of the 2D sheets of graphene potentially allows for control and manipulation of the already interesting electronic properties of 2D materials, for example by inducing a variable gap at the Dirac point of graphene. However, edge disorder has until recently proven to be a limiting factor in the widespread employment of this to create novel electronic states out of 2D materials [1].
Here, we have utilized nanoARPES at 200 nm spatial resolution to directly measure the electronic band structure of a nanopatterned graphene device built from an array of etched holes. We observe the formation of a band gap and determine how this gap varies with superstructure parameters, namely the size and spacing of the holes. Upon application of a gate voltage we see the doping of the Dirac cone and view the difference in spectral weight from the patterned regions, confirming the potential of this technique as an avenue for directly determining the electronic properties of functional, nanoengineered 2D devices.


[1] Jessen, B.S., Gammelgaard, L., Thomsen, M.R. et al. Lithographic band structure engineering of graphene. Nat. Nanotechnol. 14, 340–346 (2019)