Photoluminescence On/Off Switching of a Single Colloidal Quantum Dot Using Photochromic Diarylethene
journal contributionposted on 24.07.2020, 17:03 by Nanoka Yano, Mitsuaki Yamauchi, Daichi Kitagawa, Seiya Kobatake, Sadahiro Masuo
Photoluminescence (PL) on/off switching systems using photochromic molecules have a high potential for a wide range of applications, such as optical memories, chemo- and biosensing, and superresolution microscopy. The combination of diarylethene derivatives (DAEs) and colloidal semiconductor quantum dots (QDs) is the most promising candidate system. The PL on/off switching behavior of the systems has been observed in ensemble solutions. In this work, we investigated the PL on/off switching behavior of CdSe/ZnS core/shell QDs at the single QD level by dispersing the QDs and DAEs in a poly(methyl methacrylate) thin film. The photoswitching behavior of the PL intensity and the lifetime of single QDs accompanied by the photoisomerization of the DAE were successfully observed based on Förster-type fluorescence resonance energy transfer (FRET) from the excited QDs to the closed-ring form of the DAEs. By controlling the concentration of DAEs and the photoirradiation time for the photoisomerization of DAEs, average FRET efficiency of approximately 80% was achieved. However, a completely reversible photoswitching was difficult to achieve. Based on the PL lifetime change of the single QDs with the photoisomerization of DAEs, details of the system are discussed. The present results provide important insights into creating PL on/off switching systems using a single QD and photochromic molecules.