FABRICATION OF STRUCTURAL CONTROLLED ORGANIC THIN FILM MEMORY

有机薄膜存储器件因其低成本、高密度等优点而备受关注。本研究尝试通过分子排列和纳米颗粒排列来控制薄膜结构，从而开发新型有机存储器件。一个薄膜装置，其中的纤维素衍生物被夹在两种不同的金属，显示出一个激烈的过渡后，向前和向后扫描的外部电场的低和高电导率状态。这种可逆的电流转换行为表现出典型的存储特性，其ON/OFF（高和低电导率）状态呈现出四个数量级的电流比。此外，我们还研究了一种由有机介电层之间的有序金属纳米颗粒层组成的新型存储器。这种存储器的优点是通过改变单层金属纳米颗粒的数量来控制电荷的存储。通过朗缪尔槽在水表面形成单层金属纳米颗粒，并将其转移到有机层和/或基底上。纳米颗粒层的厚度由堆叠的数量控制。该存储器件由ITO/有机层/金属纳米颗粒层/有机层/Al组成，观察到了典型的I-V滞回曲线。随着纳米颗粒层数的增加，滞回曲线面积增大。这表明金属纳米颗粒的堆叠控制了有机存储器件中的存储量。

Organic thin film memory devices are investigated because of the advantages of low cost, high density, etc. In this study, we tried to newly develop organic memory with controlling tire thin film structure by molecular arrangement and nano-particle arrangements.First a novel functionalized cellulose derivative has been synthesized for organic memory materials. A thin film device, where the cellulose derivative is sandwiched by two different metals, shows a drastic transition between low- and high-conductivity states upon the forward and backward sweeping of an external electric field. This reversible current transition behavior demonstrates a typical memory characteristic, with the ON/OFF(high and low-conductivity) states exhibiting a current ratio of four orders of magnitude.Furthermore, we investigated a novel memory composed of ordered metal nano particle layers between organic dielectric layers. The advantage of the memory is to control the storage of electric charges by changing the number of metal nano-particles monolayer. The monolayer of metal nano-particles formed at water surface by Langmuir trough and transferred onto the organic layers and/or substrates. The thickness of nano particle layers was controlled by the number of stacking. The memory device composed of ITO/organic layer/metal nano-particle layers/organic layer/Al. As a result, we observed the typical I-V hysteresis curve as a memory effect. The area of hysteresis curve increased with increasing the stacking numbers of nano-particle layers. This indicates the stacking of metal nano particles controlled the amount of storage in organic memory device.