Fulgide Derivative-Based Solid-State Reversible Fluorescent Switches for Advanced Optical Memory

Abstract

Solid-state fluorescent switches with reversible luminescence characteristics have attracted considerable attention because of their broad applications in advanced photonics, such as anticounterfeiting inks, optical writing and erasing, and biological imaging. Herein, we have fabricated a solid-state reversible fluorescent switch under alternating UV (365 nm) and visible light treatments based on a fulgide (FUL)-functionalized tetraphenylethylene (TPE) derivative (TPE-FUL) containing a photochromic group FUL and aggregation-induced emission (AIE) luminogen TPE. TPE-FUL exhibited excellent reversible absorption and luminescence owing to the interconversion between open TPE-FUL (O-TPE-FUL) and closed TPE-FUL (C-TPE-FUL). Photophysical and theoretical investigations revealed that the luminescence of O-TPE-FUL is based on the local excited state of the TPE moiety, whereas the fluorescence quenching of C-TPE-FUL originates from the intramolecular charge transfer from the TPE to the FUL moiety. The excellent reversible photoswitching properties of TPE-FUL in the solid state allows for its potential use in advanced optical memory applications, such as anticounterfeiting, optical writing and erasing, and information encryption.