  Atomically-thin 2D semiconducting materials integrated into van der Waals
heterostructures have enabled architectures that hold great promise for next
generation nanoelectronics. However, challenges still remain to enable their
full acceptance as compliant materials for integration in logic devices. Two
key-components to master are the barriers at metal/semiconductor interfaces and
the mobility of the semiconducting channel, which endow the building-blocks of
${pn}$ diode and field effect transistor. Here, we have devised a reverted
stacking technique to intercalate a wrinkle-free h-BN tunnel layer between
MoS$_{2}$ channel and contacting electrodes. Vertical tunnelling of electrons
therefore makes it possible to suppress the Schottky barriers and Fermi level
pinning, leading to homogeneous gate-control of the channel chemical potential
across the bandgap edges. The observed unprecedented features of ambipolar
${pn}$ to ${np}$ diode, which can be reversibly gate tuned, paves the way for
future logic applications and high performance switches based on atomically
thin semiconducting channel.
