Detailed\nAtomic Reconstruction of Extended Line Defects in Monolayer MoS₂

Abstract

We\nstudy the detailed bond reconstructions that occur in S vacancies\nwithin monolayer MoS₂ using a combination of aberration-corrected\ntransmission electron microscopy, density functional theory (DFT),\nand multislice image simulations. Removal of a single S atom causes\nlittle perturbation to the surrounding MoS₂ lattice, whereas\nthe loss of two S atoms from the same atomic column causes a measurable\nlocal contraction. Aggregation of S vacancies into linear line defects\nalong the zigzag direction results in larger lattice compression that\nis more pronounced as the length of the line defect increases. For\nthe case of two rows of S line vacancies, we find two different types\nof S atom reconstructions with different amounts of lattice compression.\nIncreasing the width of line defects leads to nanoscale regions of\nreconstructed MoS₂ that are shown by DFT to behave as metallic\nchannels. These results provide important insights into how defect\nstructures could be used for creating metallic tracks within semiconducting\nmonolayer MoS₂ films for future applications in electronics\nand optoelectronics.