Optoelectronics properties of Janus SnSSe monolayer for solar cells applications

Abstract

Highly demanding efficiency, scaling and cost led the researchers to predict and synthesize two-dimensional transition metal dichalcogenides for advanced technology. Using the first-principles calculations, we study the optoelectronic properties, and device absorption efficiency of Janus SnSSe monolayer. The Janus SnSSe exist in two different phases, 1T and 2H structures. We find the 1T structure dynamically more stable than the 2H structure due lower energy and no-negative frequencies in the phonon spectra. The 1T SnSSe possess semiconducting nature with an indirect band-gap of 1.61 eV. The Janus SnSSe possesses a strong absorption having sharp absorption edges, showing the transition of electron to the conduction band from the valence band. We find that the Janus SnSSe strongly absorb light below 4.0 eV, which show its prominent applications for solar cell. A strong absorption from infra-red to the ultra-violet region of light spectrum make it promising in the optical devices. Furthermore, the wider band gap nature having strong device absorption-efficiency could make it suitable for the top cell in the tandem architecture.