Raman spectroscopy characterization of defects in 2D films of molybdenum disulfide

Molybdenum disulfide (MoS₂) is a representative of two-dimensional (2D) transition-metal dichalcogenides (TMDCs) that has promising properties for electronic and optoelectronic applications. Raman spectroscopy is a well-established technique for characterization of TMDCs providing insight into their structural properties. We used Raman spectroscopy to characterize MoS₂ films grown by atomic layer deposition on Si substrates and subsequently annealed at various conditions (temperature, duration, and environment). Analysis of MoS₂ Raman peak positions and line widths and comparison with the spectra of bulk MoS₂ crystals allows for structural quantification of two-dimensional MoS₂ layers, providing information on the crystalline quality and defect concentration. Raman results will be correlated with the processing conditions and data obtained by other characterization techniques (transmission electron microscopy, atomic force microscopy and conductivity).