Triplet energy transfer driven photoswitch systems and devices

Photoswitches, such as diarylethenes (DAEs) and azobene (AZOs), are a class of small molecules that can undergo reversible photoisomerization upon irradiation with light of different wavelengths. Conventional photoswitches typically require high-energy ultraviolet light to drive their photoisomerization. To address this limitation, we have constructed a series of all-visible-light-driven quantum dot-photoswitch systems, guided by theoretical analysis using density functional theory (DFT) calculations. Through investigation of the steady-state and transient processes in these quantum dot-photoswitch systems, we have demonstrated an ultrafast intermolecular triplet energy transfer (TET) process occurring on the picosecond timescale. Furthermore, leveraging this system, we have fabricated a range of thin-film transistor devices that integrate dual photo-electrical responses within a device. This work paves the way for next-generation technologies in information storage, smart sensing, and neuromorphic computing.