Tunable spectral properties of photodetectors based on quaternary transition metal dichalcogenide alloys MoxW(1-x)Se2yS2(1-y)

The ability to control the bandgap in two-dimensional graphene-like semiconductors is an essential task for the development of optoelectronic and nanoelectronic devices. Complex compositions alloys of transition metal dichalcogenides, such as MoxW1-x Se2yS2(1-y), are the most optimal candidates for this purpose. Here we present spectrally selective photodetectors based on such quaternary transition metal dichalcogenides monolayers. It is shown that the spectral selectivity of optical detectors can be changed in a wide range if the composition of these quaternary monolayer transition metal dichalcogenides varies. This effect is directly related to the significant influence of the composition of such two-dimensional semiconductors on their bandgap. A theoretical model for estimation of quaternary transition metal dichalcogenides optical coefficients and optical detectors on their basis is proposed. The optical absorption simulation in created detectors was made, the results of which qualitatively coincided with the detectors performance. Thus, the obtained results can contribute to the development of valleytronics for two-dimensional semiconductor structures.