  Assembling different two-dimensional (2D) crystals, covering a very broad
range of properties, into van der Waals (vdW) heterostructures enables the
unprecedented possibilities for combining the best of different ingredients in
one objective material. So far, metallic, semiconducting, and insulating 2D
crystals have been used successfully in making functional vdW heterostructures
with properties by design. Here, we expand 2D superconducting crystals as a
building block of the vdW hererostructures. A one-step growth of large-scale
high-quality vdW heterostructures of graphene and 2D superconducting a-Mo2C by
using chemical vapor deposition (CVD) method is reported. The superconductivity
and its 2D nature of the heterostructures are characterized by our scanning
tunneling microscopy (STM) measurements. This adds the 2D superconductivity,
the most attractive property of condensed matter physics, to the vdW
heterostructures.
