Tunable photoelectric properties of monolayer MoWTe alloys: a first-principles study

Monolayer MoTe 2 and WTe 2 within the two-dimensional transition metal dichalcogenides (TMDCs) material family exhibit broad potential for application in optoelectronic devices owing to their direct band gap characteristics. In this work, upon alloying these materials into a monolayer system denoted as Mo 1− x W x Te 2 , intriguing alterations are observed in the electronic and optoelectronic properties. The photoelectric attributes of these alloys can be tailored by manipulating the respective ratios of molybdenum to tungsten (Mo/W). This investigation employs first-principles calculations based on density functional theory (DFT) to assess physical traits of two-dimensional monolayered structures composed from varying compositions of Mo 1− x W x Te 2 . Our findings reveal that while maintaining a direct band gap characteristic across all compositions studied, there is also a reduction observed in electron effective mass near the Fermi level. Moreover, changing in the Mo/W ratio allows gradual adjustments in electronic properties such as density of states (DOS), work function, dielectric function, absorptivity, and reflectivity. Phonon dispersion curves further demonstrate the stability of Mo 1− x W x Te 2 systems. Notably, Mo 0.5 W 0.5 Te 2 exhibits lower polarizability and reduced band gap when compared against MoTe 2 and WTe 2 counterparts. This research underscores how alloying processes enable customizable modifications in the electronic and optoelectronic properties of Mo 1− x W x Te 2 monolayer materials which is essential for enhancing nanoscale electronic and optoelectronic device design. Changes in electronic and optoelectronic properties of monolayer system of Mo 1− x W x Te 2 .