Realizing the Conversion of Resistive Switching Behavior from Binary to Ternary by Adjusting the Charge Traps in the Polymers

Functional polymer materials have shown great application potential in the field of information storage. Nevertheless, the majority of polymer-based memory devices are restricted to binary storage and exhibit limited capacity. In this study, naphthalene benzimidazole acceptor units were connected to fluorene/carbazole donor, and four new donor–acceptor bipolar-conjugated copolymers were achieved via the Suzuki cross-coupling reaction. Compared with pure fluorene/carbazole polymers, these polymers used in storage devices exhibit a special ternary-resistance switch memory mechanism, and their switching current ratios are high, which are 1:101.5:104, 1:101.5:104.3, 1:101.7:105.5, and 1:102.1:105.1. The low threshold voltages are −1.00 V/–1.60 V, −0.60 V/–1.20 V, −1.00 V/–1.45 V, and −0.65 V/–1.25 V. The mechanism of resistance switching is explained in detail by the charge trap model. This study contributes to an insight for rationally designing and manufacturing efficient memory devices that have multilevel transition states.