Deciphering Erasing/Writing/Reading of Near-Infrared Fluorophore for Nonvolatile Optical Memory.

A near-infrared fluorescence-switchable molecule, dithienylethene-terrylenediimide (TDI-4DTE) exhibits high near-infrared fluorescence and on/off ratio, decent reversibility, and fatigue resistance upon alternating UV/vis (305/621 nm) irradiation. Photoinduced electron transfer mainly contributes to the fluorescence quenching of TDI-4DTE. As an information storage unit, single molecular TDI-4DTE in the polymer film can be written by red light (621 nm) and erased by UV light (305 nm), while nondestructive fluorescence readout (750 nm) of a single molecular memory has been obtained upon excitation with near-infrared light (720 nm). The fluorescence patterning of TDI-4DTE in the polymer film demonstrates that the erasing/writing/reading wavelengths are deciphered to minimize the signal crosstalk in nonvolatile fluorescent molecular memories.