Surface-Enhanced Raman Scattering Monitoring of Oxidation States in Defect-Engineered Two-Dimensional Transition Metal Dichalcogenides.

Recent studies have found that some transition metal dichalcogenides (TMDs) with their own defects are difficult to store in the air for a long time. Worse stability of TMDs under extreme conditions has also been reported. Therefore, monitoring the oxidation and degradation processes of TMDs can directly guide the stability prediction of TMD-based devices and monitor TMDs quality. Herein, with the case of molybdenum disulfide, UV-ozone defect engineering is used to simulate the oxidation and degradation of TMDs under severe conditions. Surface-enhanced Raman scattering based on a chemical mechanism was first introduced to the dynamic monitoring of defect evolution in the oxidation and degradation of TMDs, and succeeds in tracking the TMDs oxidation state by the quantitative method. It is expected that this technology can be extended to the quantification and tracking of oxidation and degradation of other 2D materials.