Abstract
We study the effects of chemical treatment with bis(trifluoromethane) sulfonimide superacid on material and device properties of monolayer molybdenum disulfide grown by chemical vapor deposition. Our spatially resolved photoluminescence (PL) measurements and device studies reveal two key findings due to the chemical treatment: (1) noticeable transformation of trions to neutral excitons, and (2) over 7-fold reduction in the density of mid-gap trap states. Specifically, a combination of scanning Auger microscopy and PL mapping reveals that the superacid treatment is effective in passivating the sulfur-deficient regions. Published by AIP Publishing.