Wang Ming, Li Zhuang, Li Hua, He Jinghui, Li Najun, Xu Qingfeng, Lu Jianmei
College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 215123, P. R. China.
Chem Asian J. 2017 Oct 18;12(20):2744-2748. doi: 10.1002/asia.201701044. Epub 2017 Sep 21.
Herein, novel random copolymers PMNN and PMNB were designed and synthesized, and the memory devices Al/PMNN and PMNB/ITO both exhibited ternary memory performance. The switching voltages of the OFF-ON1 and ON1-ON2 transitions for both memory devices are around -2.0 and -3.5 V, respectively, and the ON1/OFF, ON2/ON1 current ratios are both up to 10 . The observed tristable electrical conductivity switching could be attributed to field-induced conformational ordering of the naphthalene rings in the side chains, and subsequent charge trapping by 1,8-naphthalimide moieties. More interestingly, by adjusting the connection sites of 1,8-naphthalimide moieties to tune the steric-twist effect, different memory properties were achieved (PMNN showed nonvolatile write once, read many (WORM) memory behavior, whereas PMNB showed volatile static RAM (SRAM) memory behavior). This result will offer a guideline for the design of different high-performance multilevel memory devices by tuning the steric effects of the chemical moieties.
在此，设计并合成了新型无规共聚物PMNN和PMNB，且存储器件Al/PMNN和PMNB/ITO均表现出三元存储性能。两种存储器件的关-开1和开1-开2转变的开关电压分别约为-2.0 V和-3.5 V，且开1/关、开2/开1电流比均高达10。观察到的三稳态导电开关可归因于侧链中萘环的场诱导构象有序化，以及随后1,8-萘二甲酰亚胺部分的电荷俘获。更有趣的是，通过调整1,8-萘二甲酰亚胺部分的连接位点来调节空间扭曲效应，实现了不同的存储特性（PMNN表现出非易失性一次写入、多次读取（WORM）存储行为，而PMNB表现出易失性静态随机存取存储器（SRAM）存储行为）。这一结果将为通过调节化学部分的空间效应来设计不同的高性能多级存储器件提供指导。
