Improving the ON/OFF Ratio and Reversibility of Recording by Rational Structural Arrangement of Donor–Acceptor Molecules

Abstract Organic molecules with donor–acceptor (D–A) structure are an important type of material for nanoelectronics and molecular electronics. The influence of the electron donor and acceptor units on the electrical function of materials is a worthy topic for the development of high‐performance data storage. In this work, the effect of different D–A structures (namely D–Π–A–Π–D and A–Π–D–Π–A) on the electronic switching properties of triphenylamine‐based molecules is investigated. Devices based on D–Π–A–Π–D molecules exhibit excellent write–read–erase characteristics with a high ON/OFF ratio of up to 10⁶, while that based on A–Π–D–Π–A molecules exhibit irreversible switching behavior with an ON/OFF ratio of about (3.2 × 10¹)–(1 × 10³). Moreover, long retention time of the high conductance state and low threshold voltage are observed for the D–A switching materials. Accordingly, stable and reliable nanoscale data storage is achieved on the thin films of the D–A molecules by scanning tunneling microscopy. The influence of the arrangement of the D and A within the molecular backbone disclosed in this study will be of significance for improving the electronic switching properties (ON/OFF current ratio and reversibility) of new molecular systems, so as to achieve more efficient data storage through appropriate design strategies.