Characterization of Molybdenum Disulfide (MoS 2 ) Using Raman and UV-VIS Spectroscopy forOptoelectronic Applications

Atomically thin 2D-transitions metal dichalcogenides (TMDs) exhibit unique

optical, mechanical, and transport properties. Among the different types of 2D-

TMDs, monolayer MoS 2 has attracted enormous attention due to its non-zero

bandgap and absorption in the visible spectrum. We have investigated the optical

properties and thickness dependence of MoS₂ thin films using Raman and UV-VIS

spectroscopy. Our investigations reveal that the E 1 2g (in-plane) and A 1g (out-of-plane)

vibrational modes appear as Raman peaks between 384-387 cm⁻¹ and 403-408

cm⁻¹, respectively. The intensity ratio of the Raman peaks, approximately 1,

confirmed the monolayer structure of the sample. Furthermore, UV-VIS

spectroscopy was used to obtain the energy band gap of the MoS₂ thin films

through the Tauc plot method. A strong optical absorption feature at lower

wavelengths was observed near the ultraviolet region, indicating the material's

potential for photodetection and energy harvesting abilities at this wavelength.

These findings confirm the utility of combining Raman and UV-VIS spectroscopy for

characterizing MoS 2 samples and investigating its tunability, driven by its layer-

dependent band gap, and thereby making it useful for high-performance

optoelectronic applications, such as UV photodetectors and flexible electronics.