Graphene/g-GeC bilayer heterostructure: Modulated electronic properties and interface contact via external vertical strains and electric fileds

Using DFT calculations, we perform the modulated electronic properties and interface contact in the graphene/GeC heterostructure by tuning the interlayer spacing, along with the application of an external electric field. The graphene/GeC interface is examined to be dominated by the van der Waals (vdW) force with equilibrium interlayer spacing of 3.413 Å and binding energy per C atom of approximately −50 meV. This indicates graphene/GeC nanostructure a type of vdW heterostructure (vdWH). A direct band gap up to 6 meV is opened at the Dirac point, with the Dirac point well preserved, suggesting its significant application as a suitable candidate in nano-electronic and optoelectronic devices. Moreover, the graphene/GeC vdWH forms a p-type Schottky contact at the equilibrium state with a Schottky barrier height (SBH) of 0.14 eV. A transition for the interface contact from Schottky to Ohmic can be achieved by modifying the interlayer spacing smaller than 3.20 Å or applying a positive electric field of 0.1–0.7 V Å−1. Interestingly, the p-type SBH (1.00 eV) can be tailored extensively approaching to the n-type SBH (1.09 eV) when negative electric field strengthened to 0.63 V Å−1, demonstrating it substantial potential for the transition of Schottky contact from p-type to n-type. The findings are crucial for designing new nano-electronic devices comprising graphene-based vdWHs, which ascribes to the feasibility for application of tunable vertical strain and electric field in industrial applications. In this contribution, we explore the modulated electronic properties and interface contact in the graphene/GeC bilayer heterostructure by DFT calculations. A direct band gap up to 6 meV is opened at the Dirac point in the graphene/GeC vdWH, with the Dirac point well preserved. Interestingly, a transition for the interface contact from Schottky contact to Ohmic one is presented by modifying the interlayer spacing smaller than 3.20 Å or inserting a positive external electric field from 0.1 to 0.7 V Å−1. The p-type SBH (1.00 eV) is tailored extensively approaching to n-type SBH (1.09 eV) when the negative electric field is up to 0.63 V Å−1, indicating the transition for the Schottky contact from p-type to n-type. These findings demonstrate the efficient controlling of great practical possibility for the types of interface contact, which is extensively crucial for designing and fabricating novel nano-electronic devices formed by graphene-based vdW heterostructures(a) Theor