Excitons and light-emission in semiconducting MoSi2X4 two-dimensional materials

Abstract Semiconducting two-dimensional materials with chemical formula MoSi 2 X 4 (X = N, P, or As) are studied by means of atomistic ground- and excited-state first-principles simulations. Full-fledged quasi-particle bandstructures within the G 0 W approach substantially correct electronic bandgaps previously obtained hybrid-functional density functional theory highlight absence lateral valleys close in energy to conduction band minimum. By solving Bethe–Salpeter equation, we show that optical properties dominated strongly bound excitons absorbance maximum short-circuit current densities P As comparable those transition metal dichalcogenides. Due presence outer SiX layers, exciton binding energies smaller than generally found for Long radiative lifetimes bright excitons, over 10 ns at room temperature , band-nesting very promising application efficient ultra-thin optoelectronic devices.