Induced magnetic states upon electron-hole injection at B and N sites of
hexagonal Boron Nitride bilayer: A DFT study
We have reported the electronic, magnetic, and optical properties of the
top layer carbon-doped hexagonal Boron Nitride(h-BN) bilayer at
B/N-sites using the density functional theory implemented in Quantumwise
VNL-ATK package. The calculated structural and electronic properties of
the h-BN bilayer are in agreement with the previously reported results.
A single carbon doping on B and N sites modifies the large band gap
semiconducting behaviour of h-BN bilayer similar to dilute magnetic
semi-conducting material with a net magnetic moment of 1.001 μ B and
0.998 μ B , respectively. For double doping at B/N sites net magnetic
moment increases to 1.998 μ B and 1.824 μ B , respectively. Whereas for
triply carbon doped bilayer system at B/N sites, the system changes to
metallic behaviour. Upon carbon doping at N-site, we obtained transition
from Non-Magnetic semiconductor(Pristine) → Magnetic semiconductor(1C) →
Half-Metal ferromagnetic(2C) → Metal(3C). Whereas, in case of doping at
the B-site, we observed transition from Non-Magnetic
Semiconductor(Pristine) → Magnetic Semiconductor(1C) → Metal (2C, 3C).
Analysis from the PDOS plot of the car- bon doped systems reveals that
the net magnetic moments are contributed by the 2p orbitals of carbon
and partial contribution from the neighboring nitrogen and boron atoms,
respectively. As 1,2C doping at the B-site reduces the energy band gap
to 0.81-1.8 eV which falls in the visible spectrum and thus such system
further opens up an opportunity to be utilised as a photocatalys
material. Our carbon doped systems show a magnetic semiconducting
behavior with a nite magnetic moment which is one of the criteria for a
spintronic material. So, our system looks promising in this regard.
Also, Carbon doping can be considered as a simple approach to tune the
band gap of the Boron Nitride bilayer system.