Enhancement of luminescence properties and stability in perovskite hybrid structure with CdSe/ZnS quantum dots

초록

Semiconductor core-shell quantum dots (QDs) have been employed to enhance the optical properties and stability of perovskite (PS). The exciton behaviors in PS are influenced by its surface properties; therefore, the mechanisms of exciton recombination in this material should be studied in order to utilize PS-based optoelectronic devices effectively. We investigated the charge transfer from CdSe/ZnS core-shell QDs to organic-inorganic mixed halide PS using temperature-dependent photoluminescence (PL) and time-resolved PL spectroscopy. The PL intensity of the PS in the QD/PS hybrid structure increased to approximately 2.4 times that of the bare PS. In addition, the PL decay time of the PS in the QD/PS hybrid structure increased about 5.4 times (4.05 ns) compared to that (0.75 ns) in the bare PS, while the decay time of the QDs in the hybrid structure greatly reduced to 2.94 from 4.84 ns in the bare QDs. The enhancement of the PL intensity and decay time of the PS in the QD/PS hybrid structure are attributed to charge transfer from QDs and the decrease in defect states. A charge transfer efficiency of approximate to 39% was determined from QDs to the PS layer in the QD/PS hybrid structure at 300 K.

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