Charge and energy transfer dynamics in single colloidal quantum dots/monolayer MoS 2 heterostructures.

The charge and energy transfer dynamics in colloidal CdSeTe/ZnS quantum dots (QDs)/monolayer molybdenum disulfide (MoS 2 ) heterostructures have been investigated by time-resolved single-dot photoluminescence (PL) spectroscopy. A time-gated method is used to separate the PL photons of single QDs from the PL photons of monolayer MoS 2 , which are impossible to be separated by the spectral filter due to their spectral overlap. It is found that the energy transfer from MoS 2 to single QDs increases the exciton generation of the QDs by 37.5% and the energy transfer from single QDs to MoS 2 decreases the PL quantum yield of the QDs by 66.9%. In addition, it is found that MoS 2 increases the discharging rate of single QDs by 59%, while the charging rate remains unchanged. This investigation not only provides valuable insight into the exciton generation and recombination at the single-dot level across such hybrid 0D-2D interfaces but also promotes the application of the hybrid system in various optoelectronic devices.