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

The charge and energy transfer dynamics in colloidal CdSeTe/ZnS quantum dots (QDs)/monolayer molybdenum disulfide (MoS) 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, which are impossible to be separated by the spectral filter due to their spectral overlap. It is found that the energy transfer from MoS to single QDs increases the exciton generation of the QDs by 37.5% and the energy transfer from single QDs to MoS decreases the PL quantum yield of the QDs by 66.9%. In addition, it is found that MoS 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.