Band gap renormalization and work function tuning in MoSe2/hBN/Ru(0001) heterostructures

摘要

Here we report the successful growth of MoSe2 on single layer hexagonal boronnitride (hBN) on Ru(0001) substrate by using molecular beam epitaxy. Weinvestigated the electronic structures of MoSe2 using scanning tunnelingmicroscopy and spectroscopy. Surprisingly, we found that the quasi-particle gapof the MoSe2 on hBN/Ru is about 0.25 eV smaller than those on graphene orgraphite substrates. We attribute this result to the strong interaction betweenhBN/Ru which causes residual metallic screening from the substrate. The surfaceof MoSe2 exhibits Moir\'e pattern that replicates the Moir\'e pattern ofhBN/Ru. In addition, the electronic structure and the work function of MoSe2are modulated electrostatically with an amplitude of ~ 0.13 eV. Mostinterestingly, this electrostatic modulation is spatially in phase with theMoir\'e pattern of hBN on Ru(0001) whose surface also exhibits a work functionmodulation of the same amplitude.