Enhanced mechanical reliability of defect-repaired and passivated 2D semiconductors

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are semiconductors which exhibit a relatively high density of defects, mainly in the form of chalcogen vacancies^1,2. This high density of defects hinders the long-term reliability of their mechanical and electronic characteristics^3–5. Here, we utilize a quick and straightforward pretreatment process that repairs and passivates vacancy defect sites in 2D TMDs. We employ atomic force microscopy (AFM)-based nanomechanical experiments and Weibull statistics to demonstrate that repairing and passivating vacancies significantly improves the mechanical reliability, particularly static fatigue, of monolayer molybdenum disulfide (MoS₂) and tungsten disulfide (WS₂). In addition, ab initio molecular dynamics (AIMD) simulations, X-ray photoelectron spectroscopy (XPS), and atomic-scale imaging using conductive atomic force microscopy (C-AFM) provide deeper insights into the mechanisms involved in defect repair, passivation, and the fatigue response of these 2D semiconductors.



References

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