  Achieving large-area uniform two-dimensional (2D) metal-organic frameworks
(MOFs) and controlling their electronic properties on inert surfaces is a big
step towards future applications in electronic devices. Here we successfully
fabricated a 2D monolayer Cu-dicyanoanthracene (DCA) MOF with long-range order
on an epitaxial graphene surface. Its structural and electronic properties are
studied by low-temperature scanning tunneling microscopy (STM) and spectroscopy
(STS) complemented by density-functional theory (DFT) calculations. We
demonstrate access to multiple molecular charge states in the 2D MOF using
tip-induced local electric fields. We expect that a similar strategy could be
applied to fabricate and characterize 2D MOFs with exotic, engineered
electronic states.

Materials Science;Mesoscale and Nanoscale Physics