The Thermo Scientific CISA (Correlative Imaging and Surface Analysis) workflow was used to analyse MoS2 2D-crystals, deposited on a silicon oxide surface. CISA combines scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) in a single correlated and time efficient workflow that can not only provide imaging and surface analysis but can also incorporate complimentary techniques, such as Raman spectroscopy.
In this case study the Nexsa G2 surface analysis system and the Axia ChemiSEM were utilized. The combined application of XPS, Raman and SEM in the CISA workflow enabled high resolution imaging as well as the chemical identification of the sample surface at identical regions of interest (ROI's).
As a result, both the surface chemistry and the structure of MoS2 on silicon oxide were clearly determined. It was also shown that both MoS2 and MoO3 were present, and that there is a variation in the number of layers at different regions of the surface.