Unveiling the properties of transition-metal dichalcogenides: a comprehensive study of WTe2, WSe2, ZrTe2, and NiTe2 in bulk and monolayer forms

This study conducts a thorough examination of the properties of four transition-metal dichalcogenides (TMDCs): WTe2, WSe2, ZrTe2, and NiTe2, using first-principles density functional theory calculations. The results reveal that WSe2 and WTe2 exhibit semiconducting behavior in both bulk and monolayer forms, while ZrTe2 and NiTe2 exhibit metallic behavior in their bulk forms. However, a deviation from metallic behavior is observed in the monolayer form of NiTe2. The study also delves into the optical characteristics of both bulk and monolayer forms, including dielectric function, reflectivity, absorption coefficient, refraction coefficient, and electron energy loss function. These findings provide a comprehensive understanding of the properties of these TMDCs, which can be utilized in the design of advanced optoelectronic devices. Moreover, the observed decrease in absorption coefficient in the monolayer forms of these TMDCs can be leveraged for transparent conductor technology. Overall, this study presents a detailed analysis of the properties of TMDCs, highlighting their potential for technological exploitation in a wide range of optoelectronic applications.