优化基于PVP的有机双稳态存储器的电性能

Optimization of Electrical Properties of Organic Bistable Memory Based on PVP

在未来非易失性存储器的应用中,有机双稳态存储器具有良好的发展潜力,但仍缺少对提升存储器性能的简单方法的探究。制备了一系列基于聚(4-乙烯基苯酚)(PVP)的三明治结构的柔性存储器,发现结构为氧化铟锡(ITO)/聚(3-己基噻吩)(P3HT)(二氯苯(DCB))/PVP/Cu的存储器写入电压最低。使用全溶液方法在柔性基底上制备此结构的存储器,并测试了其电性能。结果表明,写入电压为1.0 V,开关(ON/OFF)比为1×10^(5),保留时间达到2×10^(4)s。同时,通过分析其开关机理解释了结构和材料影响存储器性能的原理,加入修饰层P3HT和将金属电极由Al改为Cu,均可使介电层和电极之间的能级更匹配,从而降低载流子运输需克服的势垒;使用X射线衍射仪(XRD)和紫外-可见(UV-Vis)光谱仪验证了将P3HT的溶剂氯苯换为二氯苯,可增强P3HT分子的有序形态和结晶度,从而提高电荷传输能力以降低存储器写入电压。这将从设计材料和优化结构方面为提高有机存储器性能提供参考。

In the future applications of non-volatile memories,organic bistable memories have good development potential.However,there is still a lack of research on simple methods to improve the performances of memories.A series of flexible memories with sandwich structure based on poly(4-vinylphenol)(PVP)were prepared.It is found that the writing voltage of the memory with indium tin oxide(ITO)/poly(3-hexylthiophene)(P3HT)(dichlorobenzene(DCB))/PVP/Cu is the lowest.The memory with the structure was prepared on flexible substrates by the all-solution method and its electrical properties were tested.The result shows that the writing voltage is 1.0 V,the ON/OFF ratio is 1×10^(5),and the retention time reaches 2×10^(4)s.Meanwhile,the principle that the structures and materials affect the performance of the memory was explained by analyzing the switching mechanism.Adding the modification layer P3HT and changing the metal electrode from Al to Cu,the energy levels between the dielectric layer and electrode can be better matched,thus reducing the potential barrier to be overcome in carrier transport.Test results of X-ray diffractometer(XRD)and ultraviolet-visible(UV-Vis)spectrometer show that by replacing chlorobenzene with dichlorobenzene as the solvent of P3HT,the ordered morphologies and crystallinities of P3HT molecules can be enhanced,thus improving the charge transport capacity to reduce the writing voltage of the memory.It will provide reference for improving the performances of organic memories from the aspects of designing materials and optimizing structures.