Exciton and trion in 2D transition metal dichalcogenides

Abstract

Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) semiconductors such as MoS2, MoSe2, WS2,WSe2 have established themselves as strong contenders for next-generation electronics and optoelectronics and they have aroused great attention due to their peculiar physical properties, in particular the strong electron-hole interaction. We present a theoretical model based on non-local dielectric screening potential to show the impact of the screening length and the reduced mass on the exciton binding energy. We will also determine the oscillator strength and the photoluminescence (PL) line shape in order to compare between the four TMDs types and to prove that they have a large trion binding energy.