Characterization of Molybdenum (IV) Sulfide Prepared by Chemical Vapor Deposition Using Differential Reflectance Spectroscopy

Molybdenum (IV) sulfide is widely employed in electronic device applications. Recognized as one of the most efficacious methods for fabricating high-quality molybdenum (IV) sulfide, the chemical vapor deposition (CVD) method's application necessitates the development of a straightforward, swift and nondestructive characterization tool. Thus, this paper presents a rapid and reliable differential reflectance spectroscopy (DRS) instrumentation, grounded on the optical microscope, capable of characterizing two-dimensional materials prepared by CVD. This universal nondestructive identification tool facilitates the investigation of two-dimensional materials on both opaque and transparent substrates. MoS2 samples prepared by CVD were characterized on SiO2/Si and sapphire substrate. The results indicate that the exciton absorption peak can be accurately identified, validating the instrumentation's utility for material detection and monolayer identification. The characterization results, corroborated by the Raman spectra with a wavenumber difference of approximately 20 cm−1 and the triangular appearance of the optical image, affirm the application of this instrumentation. Ultimately, the DRS instrumentation provides a swift and nondestructive route to characterize physical properties such as bandgap and optical properties for two-dimensional materials.