Uniform nucleation and epitaxy of bilayer molybdenum disulfide on sapphire.

Two-dimensional transition-metal dichalcogenides (TMDs) are of interest for beyond-silicon electronics. It has been suggested that bilayer TMDs, which combine good electrostatic control, smaller bandgap and higher mobility than monolayers, could potentially provide improvements in the energy-delay product of transistors. However, despite advances in the growth of monolayer TMDs, the controlled epitaxial growth of multilayers remains a challenge.