Role of oxadiazole moiety in different D–A polyazothines and related resistive switching properties
作者:Liang Pan、Benlin Hu、Xiaojian Zhu、Xinxin Chen、Jie Shang、Hongwei Tan、Wuhong Xue、Yuejin Zhu、Gang Liu、Run-Wei Li
DOI:10.1039/c3tc30826j
日期:——
Two donorâacceptor (DâA) polyazothines (PAs), incorporating the oxadiazole entity either acting as an electron acceptor (A) to form DâA structured PA-1 with the triphenylamine donor (D), or acting as a donor to form DâA structured PA-2 with the 3,3â²-dinitro-diphenylsulfone acceptor, have been successfully synthesized via a polycondensation reaction. The variation in the role of the oxadiazole moiety in the DâA polymers, together with the use of different top electrode metals, leads to interesting electronic transport properties and various resistive switching behaviors of the present polyazothines. Pt-electrode devices based on a PA-1 active layer show a rewritable memory effect with poor endurance (less than 20 cycles), whereas the PA-2 based Pt devices exhibit write-once read-many-times (WORM) memory behavior. For the Al-electrode devices, both PAs demonstrate a much improved resistive switching effect, and the endurance of the PA-2 devices is better than that of the PA-1 devices. The difference in the electronic transport and memory properties of the four devices may originate from the different charge injection/extraction and electron transfer processes of the sandwich systems, and will provide guidelines for selecting both the proper D and A moieties in DâA polymers and electrode metals for high-performance resistance random access memories (RRAMs).
我们通过缩聚反应成功合成了两种供体-受体(DâA)多氮杂环丁烷(PA),其中的噁二唑实体既可以作为电子受体(A)与三苯胺供体(D)形成 DâA 结构的 PA-1,也可以作为供体与 3,3â²-二硝基二苯砜受体形成 DâA 结构的 PA-2。由于 DâA 聚合物中噁二唑分子的作用不同,再加上使用了不同的顶层电极金属,这些聚氮杂蒽具有有趣的电子传输特性和各种电阻开关行为。基于 PA-1 活性层的铂电极器件显示出可重写的记忆效应,但耐久性较差(少于 20 个周期),而基于 PA-2 活性层的铂器件则显示出一次写入多次读取(WORM)的记忆行为。对于铝电极器件,两种 PA 都显示出更佳的电阻开关效应,而且 PA-2 器件的耐用性优于 PA-1 器件。这四种器件在电子传输和存储特性方面的差异可能源于夹层系统不同的电荷注入/抽取和电子转移过程,这将为高性能电阻随机存取存储器(RRAM)的 DâA 聚合物和电极金属中选择适当的 D 和 A 分子提供指导。