Electric-field-driven dual-functional molecular switches in tunnel junctions
Electric-field-driven dual-functional molecular switches in tunnel junctions
复制标题
DOI：
10.1038/s41563-020-0697-5
复制
发表时间：
2020-06-01
期刊：
影响因子：
41.2
通讯作者：
Nijhuis, Christian A.
中科院分区：
文献类型：
--
作者：
Han, Yingmei;Nickle, Cameron;Nijhuis, Christian A.
为了避免串扰并抑制电阻式随机存取存储器（RRAM）中的泄漏电流，电阻开关和电流整流器（二极管）通常串联组合在一个二极管-一个电阻器（1D-1 R）RRAM中。然而，这使下一代RRAM的设计复杂化，增加了器件的占用空间，并且随着两个连续结上的电位下降而增加了工作电压（1）。在这里，我们报告了一种基于分子的分子隧道结，该分子提供了前所未有的二极管和可变电阻器的双重功能，从而产生了具有2.5 x 10（4）的电流整流比和6.7 x 10（3）的电阻开/关比以及0.89 V的低驱动电压的分子级1D-1 R RRAM。开关依赖于氧化还原单元的二聚化，导致伴随定向离子迁移的分子轨道杂化。这种电场驱动的分子开关工作在隧穿区，可以在厚度仅为2 nm的单个分子层内实现多个电子功能的分子器件，利用兼具二极管和可变电阻功能的多功能分子制备了厚度为2 nm的紧凑型分子开关，具有良好的电流整流和电阻开/关比，并且需要低至0.89V的驱动电压。
To avoid crosstalk and suppress leakage currents in resistive random access memories (RRAMs), a resistive switch and a current rectifier (diode) are usually combined in series in a one diode-one resistor (1D-1R) RRAM. However, this complicates the design of next-generation RRAM, increases the footprint of devices and increases the operating voltage as the potential drops over two consecutive junctions(1). Here, we report a molecular tunnel junction based on molecules that provide an unprecedented dual functionality of diode and variable resistor, resulting in a molecular-scale 1D-1R RRAM with a current rectification ratio of 2.5 x 10(4) and resistive on/off ratio of 6.7 x 10(3), and a low drive voltage of 0.89 V. The switching relies on dimerization of redox units, resulting in hybridization of molecular orbitals accompanied by directional ion migration. This electric-field-driven molecular switch operating in the tunnelling regime enables a class of molecular devices where multiple electronic functions are preprogrammed inside a single molecular layer with a thickness of only 2 nm.A multifunctional molecule acting both as diode and variable resistor is used to fabricate compact molecular switches with a thickness of 2 nm, good current rectification and resistive on/off ratio, and requiring a drive voltage as low as 0.89 V.