Charge transfer mechanism on MoS_2 nanosheets in the presence of a semiconductor photoactive media

The studies of the nonlinear optical (NLO) properties of the transition metal dichalcogenides (TMDs) coupled with photoactive particles, plasmonic nanocavities, waveguides, and metamaterials remain in their infancy. This study investigates the third-order NLO properties of MoS_2 nanosheets in the presence of a semiconductor photoactive medium. Our extensive studies and the obtained results reveal the counteractive coupling effect of bare and passivated quantum dots on the MoS_2 nanosheet, as made evident by the analysis of the NLO processes. The enhanced NLO properties of MoS_2 nanosheets functionalized with CdSe and CdSe-V2O5 quantum dots are helpful for applications as saturable absorbers in laser applications and the emission of coherent short-wavelength radiation. The multiphoton-excitation resonance energy transfer mechanism exploiting remote dipole dipole coupling, and ultrafast charge transfer pathways emerges as another plausible way to alter the NLO properties in TMDs.