Shell-dependent hole transport in highly luminescent CdSe-core CdS/ZnCdS/ZnS multi-shell nanocrystals

The photoinduced hole transfer dynamics from CdSe quantum dots (QDs), shelled with ZnS or CdS/CdZnS/ZnS layers, to organic hole transporting materials (HTMs) is investigated by absorption, steady-state and time-resolved photoluminescence (PL) spectroscopy. The PL intensity and lifetime of the QDs are dramatically quenched when HTMs are added into the dilute QD solution. The quenching efficiency of the QDs significantly decreases with increasing the shell thickness and increases with decreasing the oxidation potential of the HTMs. These facts are correlated with the photoinduced hole transfer from the QDs to the HTMs. The above results are helpful in understanding the photoexcitation dynamics-related phenomena of organic molecule conjugated nano-object.