  We present a novel transparent conductive support structure for
two-dimensional (2D) materials that provides an electronically passive 2D/3D
interface while also enabling facile interfacial charge transport. This
structure, which comprises an evaporated nanocrystalline carbon (nc-C) film
beneath an atomic layer deposited alumina (ALD AlOx) layer, is thermally stable
and allows direct chemical vapor deposition (CVD) of 2D materials onto the
surface. When the nc-C/AlOx is deposited onto a 270 nm SiO2 layer on Si, strong
optical contrast for monolayer flakes is retained. Raman spectroscopy reveals
good crystal quality for MoS2 and we observe a ten-fold photoluminescence
intensity enhancement compared to flakes on conventional Si/SiO2. Tunneling
across the ultrathin AlOx enables interfacial charge injection, which we
demonstrate by artifact-free scanning electron microscopy and photoemission
electron microscopy. Thus, this combination of scalable fabrication and
electronic conductivity across a weakly interacting 2D/3D interface opens up
new application and characterization opportunities for 2D materials.
