Switchable quantum dot photoluminescence across a broad spectrum with all-visible-light activated diarylethene photoswitches

Precise and reversible photoluminescence switching is highly attractive for optical memory, bioimaging, and smart displays. However, achieving broadband photoluminescence modulation through a simple and general strategy remains challenging, while the ultraviolet light requirement of most molecular photoswitches limits practical applications. Here, we achieve all-visible-light activated reversible photoluminescence modulation of quantum dots across an ultrawide spectral range of nearly 500 nm from blue to near-infrared region using diarylethene photoswitches. In the ring-open form of diarylethenes, quantum dots emitting blue, green, red, white and near-infrared light remain in the photoluminescence on-state. Under 405 nm irradiation, diarylethenes undergo ring-closure through triplet sensitization by CdS quantum dots, resulting in significant photoluminescence quenching to the off-state, with the maximum efficiency of 99.6% and an on/off ratio up to 250. Green-light irradiation reverses the diarylethenes back to the ring-open form, fully restoring the photoluminescence on-state. Our approach further enables reversible multi-level data storage and near-infrared anti-counterfeiting, highlighting the potential for smart light-responsive materials and optoelectronic devices.