Unusual Electronic Transitions in Two-dimensional Layered SnSb2Te4 Driven by Electronic State Rehybridization

The authors use density functional theory to study an ultrathick two-dimensional semiconductor, SnSb${}_{2}$Te${}_{4}$, which is predicted to have high mobility and a large optical absorption coefficient. Intriguingly, its electronic band gap exhibits an indirect-direct transition with increasing thickness. Importantly, compared to the monolayer, bilayer SnSb${}_{2}$Te${}_{4}$ possesses stronger light harvesting, higher mobility, and larger on-state current by about one order of magnitude, due to rehybridization of electronic states. These results suggest that this material is quite promising for high-performance infrared electronic and optoelectronic applications.