Department of Information Engineering, University of Brescia, Via Branze 38, 25123 Brescia, Italy.
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Nat Commun. 2017 Jun 12;8:15741. doi: 10.1038/ncomms15841.
Non-volatile memories-providing the information storage functionality-are crucial circuit components. Solution-processed organic ferroelectric memory diodes are the non-volatile memory candidate for flexible electronics, as witnessed by the industrial demonstration of a 1 kbit reconfigurable memory fabricated on a plastic foil. Further progress, however, is limited owing to the lack of understanding of the device physics, which is required for the technological implementation of high-density arrays. Here we show that ferroelectric diodes operate as vertical field-effect transistors at the pinch-off. The tunnelling injection and charge accumulation are the fundamental mechanisms governing the device operation. Surprisingly, thermionic emission can be disregarded and the on-state current is not space charge limited. The proposed model explains and unifies a wide range of experiments, provides important design rules for the implementation of organic ferroelectric memory diodes and predicts an ultimate theoretical array density of up to 10 bit cm.
非易失性存储器——提供信息存储功能——是至关重要的电路元件。溶液处理的有机铁电存储器二极管是柔性电子的非易失性存储器候选者，这一点已在工业上得到证明，即在塑料箔上制造了 1kbit 可重构存储器。然而，由于缺乏对器件物理的理解，进一步的进展受到限制，而器件物理是高密度阵列技术实现所必需的。在这里，我们表明铁电二极管在夹断时作为垂直场效应晶体管工作。隧道注入和电荷积累是控制器件工作的基本机制。令人惊讶的是，可以忽略热电子发射，并且导通电流不受空间电荷限制。所提出的模型解释并统一了广泛的实验，为有机铁电存储器二极管的实现提供了重要的设计规则，并预测了高达 10bit/cm 的理论极限阵列密度。
