Microscopical Quantification of Ion‐Induced Nanodefects in Monolayer MoS2 Based on Differential Reflectance

Abstract The defect engineering is widely used in 2D heterostructure devices as nanodefects (like atomic vacancies) significantly alter the electronic, mechanical, and optical properties of 2D nanomaterials. Defect inspection on large‐area samples at video rates is requisite for semiconductor manufacturing industry. Take molybdenum disulfide (MoS 2 ) as the study case, the differential reflectance spectroscopy (DRS) is first introduced into nanodefect quantification of 2D materials. Different densities of defects are induced by ion bombardment and the average interdefect distance L D is calibrated using Raman spectra analysis. The evolutions of several defect‐induced DRS peak/valley are interpreted based on thin‐film multilayer interference effect. Availability of the defect density mapping method is demonstrated by applying the data fitting results of DRS defect density to the monochromatic illumination microscopy images. This work provides a feasible density quantification method based on DRS mapping for 2D material nanodefects at the microscopic scale.