First-principles studies of the mixed-dimensional van der Waals heterostructures of graphene/MnF4

Constructing a mixed-dimensional (MD) graphene-based van der Waals heterostructure (vdWH) is a viable technique for opening the bandgap and introducing spin polarization in graphene. In this work, we discovered that the adjacent MnF4 can manipulate the carrier doping, bandgap opening, and spin polarization of graphene in the MD vdWH of graphene/MnF4 comprised of two-dimensional (2D) graphene and one-dimensional atomic wire (1D AW) MnF4. By adopting first-principles calculations, we found that graphene can achieve effective p-type doping with the carrier density up to similar to 8.89 x 10(13)-1.03 x 10(14) cm(-2). With a twisted angle of theta = 10.89 degrees and the compressed distance of d(mn-Gra) = 2.84 angstrom the opened bandgap of graphene (Eg-Gra) achieves 35 and 57 meV for spin-up and spin-down channels due to the sublattice symmetry-breaking in graphene, and the spin splitting energy (Delta E-s) at the Dirac point reaches 78.7 meV as a result of the graphene-MnF4 interlayer interaction. Remarkably, Eg-Gra is increased to 64 and 79 meV for spin-up and spin-down channels, and Delta E-s with 202.7 meV is obtained at d(mn-Gra) = 2.84 angstrom when the width of 1D MnF4 is doubled. Meanwhile, the n-type Ohmic contact is also realized. Our work underscores the rich interplay in the graphene/MnF4 MD vdWH and provides a significant route with fundamental insights to engineer the spintronic band properties of graphene.

Automated summary

Constructing a mixed-dimensional graphene/MnF4 van der Waals heterostructure can manipulate carrier doping, bandgap opening, and spin polarization of graphene, offering insights into engineering the spintronic band properties of graphene.