title: Visualizing Point Defects in Transition-Metal Dichalcogenides Using Optical Microscopy.
abstract: While transmission electron microscopy and scanning tunneling microscopy reveal atomic structures of point defect and grain boundary in monolayer transition-metal dichalcogenides (TMDs), information on point defect distribution in macroscale is still not available. Herein, we visualize the point defect distribution of monolayer TMDs using dark-field optical microscopy. This was realized by anchoring silver nanoparticles on defect sites of MoS2 under light illumination. The optical images clearly revealed that the point defect distribution varies with light power and exposure time. The number of silver nanoparticles increased initially and reached a plateau in response to light power or exposure time. The size of silver nanoparticles was a few hundred nanometers in the plateau region as observed using optical microscopy. The measured defect density in macroscale was ∼2 × 10(10) cm(-2), slightly lower than the observed value (4 × 10(11) cm(-2)) from scanning tunneling microscopy.
authors.forename: Hye Yun
authors.initials: HY
authors.lastname: Jeong
authors.forename: Si Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Thuc Hue
authors.initials: TH
authors.lastname: Ly
authors.forename: Gang Hee
authors.initials: GH
authors.lastname: Han
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Honggi
authors.initials: H
authors.lastname: Nam
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jiong
authors.forename: Bong Gyu
authors.initials: BG
authors.lastname: Shin
authors.forename: Seok Joon
authors.initials: SJ
authors.lastname: Yun
authors.forename: Jaesu
authors.initials: J
authors.lastname: Kim
authors.affiliation: Device Laboratory, Samsung Advanced Institute of Technology , Suwon 449-712, Korea.
authors.forename: Un Jeong
authors.initials: UJ
authors.lastname: Kim
authors.affiliation: Device Laboratory, Samsung Advanced Institute of Technology , Suwon 449-712, Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Hwang
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
keywords: Ag nanoparticle; dark-field optical microscopy; light illumination; molybdenum disulfide; point defect distribution