Ab initio density functional theory calculations are performe
d to investigate the electronic structure of MoS
2 armchair nanoribbons in the presence of an external static electric fiel
d. Such nanoribbons, which are nonmagnetic an
d semicon
ducting, exhibit a set of weakly interacting e
dge states whose energy position
determines the ban
d gap of the system. We show that, by applying an external transverse electric fiel
d,
Eext, the nanoribbon ban
d gap can be significantly re
duce
d, lea
ding to a metal鈥搃nsulator transition beyon
d a certain critical value. Moreover, the presence of a sufficiently high
density of states at the Fermi level in the vicinity of the metal鈥搃nsulator transition lea
ds to the onset of Stoner ferromagnetism that can be mo
dulate
d, an
d even extinguishe
d, by
Eext. In the case of bilayer nanoribbons we further show that the ban
d gap can be change
d from in
direct to
direct by applying a transverse fiel
d, an effect that might be of significance for opto-electronics applications.
Keywords:
d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=MoS2&qsSearchArea=searchText">MoS2; d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=nanoribbons&qsSearchArea=searchText">nanoribbons; d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=two%5C-dimensional+nanostructures&qsSearchArea=searchText">two-dimensional nanostructures; d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=magnetism&qsSearchArea=searchText">magnetism; d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=electric+field+effect&qsSearchArea=searchText">electric field effect; d="authors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=spin+crossover&qsSearchArea=searchText">spin crossover