Van der Waals Heterojunctions Containing Penta-graphene as Channel Material: Tuning the Schottky Barrier by Electrostatic Gating or Nitrogen Doping

The non-zero band gap together with other unique properties endows penta-graphene (PG) with potential for device applications. We have studied the performance of penta-graphene as the channel material contacting with graphene (G) and penta-BN₂ (P-BN₂)_, respectively, to form van der Waals heterostructures. Based on first-principles calculations, we found that the intrinsic properties of penta-graphene are preserved after stacking together, which is different from the conventional contact with metal surfaces. The stacked PG/G and PG/P-BN₂ heterostructures form n-type Schottky barriers at their vertical interfaces, while there is a negative band bending at their lateral interfaces between the contact regions and the freestanding PG, respectively. From the device point of view, we further demonstrated that an Ohmic contact can be realized by applying an external electric field or doping graphene with nitrogen atoms in PG/G system.

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