Fluorescent photoswitches are highly attractive, because they hold great promises for photonic devices and imaging. However, a limited number of reversible switches with a response to light have been achieved in the solid state. Here, we report reversible dual fluorescent photoswitching characteristics in the solid state of spiropyran (SP)−functionalized tetraphenylethene (TPE) derivatives. These photoswitches exhibit two distinct and selectively addressable states, a cyan fluorescence and a red fluorescence, which can be conveyed into each other in a reversible feature upon irradiation with alternating UV and visible light. Detailed spectroscopic and theoretical studies suggest that the nonplanar molecular conformation of TPE moieties leads to large free volumes, which facilitates the reversible photoisomerization of SP. The excellent reversibility and high-contrast fluorescence of solid-state photoswitches enable great applications in multimodality anticounterfeiting and optical writing and erasing fluorescent devices.

Fluorescent photosensitizers (PSs) often encounter low singlet oxygen (1O2) quantum yields and fluorescence quenching in aggregate state, mainly involving the intersystem crossing process. Herein, we successfully realize maximizing 1O2 quantum...

Using H 3 BO 3 as a flux, LaMgAl 11 O 19 :Mn 2+ and LaMgAl 11 O 19 :RE, Mn 2+ (RE=Eu 2+ , Gd 3+) were synthesized by solid state reaction at 1150 for 4 h. ℃ The effect of Mn 2+ on the luminescent properties excited by vacuum ultraviolet (VUV) was investigated. The strong emission spectrum excited by 147 nm is composed of peaks from Eu 2+ and Mn 2+ luminescence in LaMgAl 11 O 19 :(Eu 2+ , Mn 2+) and only Mn 2+ luminescence in LaMgAl 11 O 19 :Mn 2+ and LaMgAl 11 O 19 :(Gd 3+ , Mn 2+). The results show that the green emission of Mn 2+ becomes stronger because of efficient energy transferring from Eu 2+ and Gd 3+ to Mn 2+ .

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