  Field-effect transistors (FETs) with non-covalently functionalised molybdenum
disulfide (MoS2) channels grown by chemical vapour deposition (CVD) on SiO2 are
reported. The dangling-bond-free surface of MoS2 was functionalised with a
perylene bisimide derivative to allow for the deposition of Al2O3 dielectric.
This allowed the fabrication of top-gated, fully-encapsulated MoS2 FETs.
Furthermore, by the definition of vertical contacts on MoS2, devices, in which
the channel area was never exposed to polymers, were fabricated. The MoS2 FETs
showed high mobilities for transistors fabricated on SiO2 with Al2O3 as
top-gate dielectric. Thus, gate-stack engineering using innovative chemistry is
a promising approach for the fabrication of reliable electronic devices based
on 2D materials.
