Metal Oxide Tunneling Barriers for Printed Polymer Tunnel Diodes

该项目的目的是合成和分析印刷有机隧道二极管中的金属氧化物隧道势垒。具有负微分电阻的印刷二极管是低功率电子器件的关键元件，例如在高频、显示或存储技术中的应用。该项目的重点是一个足够的密度的缺陷状态以及界面特性，这会导致负微分电阻的可再现的定义。考虑到成本效益和有效的技术的使用，隧道势垒层的合成将通过阳极氧化（AO）完成。关于AO的最有前途的方法是已知的文献中的报告，而技术实现是相当简单的。此外，AO与将用作印刷基底的塑料箔相容。AO的工艺必须以这样的方式进行调整，即可以可再现地合成金属氧化物材料的薄层，同时实现负微分电阻行为。作为用于二极管的印刷技术，凹版印刷是特别合适的，因为可以以高产量沉积高质量的均匀层。最重要的是使隧道势垒层的性质（以及因此其合成）与印刷二极管结构相匹配。同样，必须对匹配的隧道势垒进行表征。只有这个过程才能解释印刷过程对材料及其各自属性的影响。

The aim of the project is to synthesize and analyze metal oxide tunnel barriers in printed organic tunnel diodes. Printed diodes exhibiting negative differential resistance are key components for low-power electronics, for example with applications in high frequency-, display- or memory technology. The project is focused on the reproducible definition of an adequate density of defect states as well as of interface properties, which cause a negative differential resistance. Considering the use of cost-effective and efficient techniques, the synthesis of the tunnel barrier layers will be done by anodic oxidation (AO). Most promising approaches concerning AO are known from reports in literature, whereas the technical realization is rather simple. Furthermore, AO is compatible to the plastic foil, which will be used as printing substrates. The process of the AO has to be adjusted in such a way that thin layers of a metal oxide material can reproducibly be synthesized, while a negative differential resistance behavior is achieved. As a printing technique for diodes, gravure printing is particularly suitable, because uniform layers of high quality can be deposited at high throughput. It is most essential to match the properties of the tunnel barrier layer (and hence its synthesis) to the printed diode structures. Likewise, the characterization has to be performed on the matched tunnel barrier. Only this procedure allows to account for the impact of the printing process on the materials and their respective properties.