  Certain layered transition metal dichalcogenides (TMDCs), such as 1T-TaS2,
show a rich collection of charge density wave (CDW) phases at different
temperatures, and their atomic structures and electron conductions have been
widely studied. However, the properties of CDW systems that are integrated with
other electronic materials have not yet been investigated. Here, we incorporate
the CDW properties of TMDCs into the electronic transport of graphene for the
first time. During CDW phase transitions, anomalous transport behaviors that
are closely related to the formation of correlated disorder in TMDCs were
observed in the graphene sample used in this study. In particular, the
commensurate CDW phase forms a periodic charge distribution with potential
fluctuations, and thus constitutes correlated charged impurities, which
decreases resistivity and enhances carrier mobility in graphene. The
CDW-graphene heterostructure system demonstrated here paves the way to
controlling the temperature-dependent carrier mobility and resistivity of
graphene and to developing novel functional electronic devices such as
graphene-based sensors and memory devices.
