Han Yingmei, Nickle Cameron, Zhang Ziyu, Astier Hippolyte P A G, Duffin Thorin J, Qi Dongchen, Wang Zhe, Del Barco Enrique, Thompson Damien, Nijhuis Christian A
Department of Chemistry, National University of Singapore, Singapore, Singapore.
Department of Physics, University of Central Florida, Orlando, FL, USA.
Nat Mater. 2020 Aug;19(8):843-848. doi: 10.1038/s41563-020-0697-5. Epub 2020 Jun 1.
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. 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 × 10 and resistive on/off ratio of 6.7 × 10, 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.
为了避免电阻式随机存取存储器（RRAM）中的串扰并抑制漏电流，电阻开关和电流整流器（二极管）通常在单二极管-单电阻（1D-1R）RRAM中串联组合。然而，这使得下一代RRAM的设计变得复杂，增加了器件的占地面积，并由于电势在两个连续结上下降而增加了工作电压。在此，我们报道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双重功能，从而产生了一种分子尺度的1D-1R RRAM，其电流整流比为2.5×10，电阻开/关比为6.7×10，驱动电压低至0.89V。开关依赖于氧化还原单元的二聚化，导致分子轨道杂化并伴随着定向离子迁移。这种在隧穿机制下运行的电场驱动分子开关实现了一类分子器件，其中多个电子功能被预编程在仅2nm厚的单个分子层内。
