This AFM image
shows 2D F4TCNQ islands on graphene/BN that could be used
to modify the
graphene for electronic applications.
Berkeley Lab Scientists Discovery Could Help Improve
Graphene Electronics
(December 22, 2015) In
what could prove to be a significant advance in the fabrication of
graphene-based nanodevices, a team of Berkeley Lab researchers has discovered a
new mechanism for assembling two-dimensional (2D) molecular “islands” that
could be used to modify graphene at the nanometer scale. These 2D islands are
comprised of F4TCNQ molecules that trap electrical charge in ways that are
potentially useful for graphene-based electronics.
“We’re reporting a scanning tunneling microscopy and
non-contact atomic force microscopy study of F4TCNQ molecules at the surface of
graphene in which the molecules coalesce into 2D close-packed islands,” says
Michael Crommie, a physicist who holds joint appointments with Berkeley Lab’s
Materials Sciences Division and UC Berkeley’s Physics Department. “The
resulting islands could be used to control the charge-carrier density in graphene
substrates, as well as to modify how electrons move through graphene-based
devices. They might also be used to form precise nanoscale patterns that
exhibit atomic-scale structural perfection unmatched by conventional
fabrication techniques.”