Benzothiazole derivatives containing different electron acceptors exhibiting totally different data-storage performances

Abstract

Two small conjugated molecules BTVCz–NO₂ and BTVCz, each incorporating an electron-donating carbazole group and a medium electron-withdrawing benzothiazole group, were both successfully designed and synthesized. Molecule BTVCz–NO₂ is an A1–D–A2 structure while BTVCz is a single D–A structure. Both molecules were made into thin films by spin-coating. The two films differentiated over their optical, electrochemical and morphological properties. And the fabricated device with BTVCz–NO₂ as an active material showed non-volatile ternary WORM data-storage behavior with its switching threshold voltages at −1.5 V and −2.5 V in tandom when an electrical field was applied, whereas its “counterpart” device with BTVCz as an active material exhibited volatile binary DRAM data-storage behavior with its switching threshold voltage at −1.3 V. Combined with theoretical calculation of each molecule, we conclude that different data-storage behaviors can be achieved by introducing different electron acceptors and that molecule BTVCz–NO₂, as an A1–D–A2 structure, is more likely to achieve ternary data-storage performance.