Exciton and excited-state charge transfer at 2D van der Waals interfaces

Abstract

Combination of monolayer (ML) transition metal dichalcogenides (TMDC) with molecular layers with strong light matter coupling can enhance, control, and spectrally tune the absorption and emission of such heterostructures. Essential is hereby the energy level alignment at the heterointerface that governs the transfer of electronic excitations. At interfaces with a staggered type-II energy level alignment fast excitedstate charge transfer has been utilized to enhance and spectrally expand the photoresponse of MoS2-based hybrid photodetectors. At interfaces with a straddling type-I energy level alignment, transfer of excitons on a sub-picosecond time scale results in an enhanced PL yield from ML-MoS2 in the heterostructure and an according overall modulation of the photo-response.