Point defect induced intervalley scattering for the enhancement of interlayer electron transport in bilayer MoS2 homojunctions

Abstract

Since the emergence of transition metal dichalcogenide (TMDC) based van der Waals (vdW) structures, interlayer charge transport has become an important issue towards the application of these novel materials. Due to the unique layered structure of these materials, charge transport across the vdW gaps via tunneling is governed by individual valleys with different interlayer coupling strengths. On the other hand, the omnipresent point defects in TMDCs could possibly cause intervalley scattering between these valleys. In this article, we investigate the influence of point defect induced intervalley scattering on the interlayer charge transport of the MoS₂ homojunction by first principles calculation. We find that S vacancies and Mo–S antisite defects enhance the electron interlayer transport by intervalley scattering that divert the electrons from the non-interlayer coupling K valley to the strong interlayer coupling Q valley. The interlayer charge transport enhancement caused by such an intervalley scattering mechanism could pave the way towards understanding the interlayer charge transport in TMDC based vdW structures.