Light-Triggered Switching of Quantum Dot Photoluminescence through Excited-State Electron Transfer to Surface-Bound Photochromic Molecules

This paper describes reversible on-off switching of the photoluminescence (PL) intensity of CdSe quantum dots (QDs), mediated by photochromic furylfulgide carboxylate (FFC) molecules chemisorbed to the surfaces of the QDs. Repeated cycles of UV and visible illumination switch the FFC between closed and open isomers. Reversible switching of the QDs' PL intensity by >80% is enabled by different rates and yields of PL-quenching photoinduced electron transfer (PET) from the QDs to the respective isomers. This difference is consistent with cyclic voltammetry measurements and density functional calculations of the isomers' frontier orbital energies. This work demonstrates fatigue-resistant modulation of the PL of a QD-molecule complex through remote control of PET. Such control potentially enables applications, such as all-optical memory, sensing, and imaging, that benefit from a fast, tunable, and reversible response to light stimuli.

Automated summary

This paper describes reversible on-off switching of the photoluminescence intensity of CdSe quantum dots mediated by photochromic furylfulgide carboxylate molecules chemisorbed to the QDs' surfaces. The switching is enabled by different rates and yields of PL-quenching photoinduced electron transfer from the QDs to the isomers, consistent with cyclic voltammetry measurements and density functional calculations. This work demonstrates fatigue-resistant modulation of the PL of a QD-molecule complex through remote control of PET, enabling potential applications like all-optical memory, sensing, and imaging with a fast, tunable, and reversible response to light stimuli.