Kong Gyu Don, Jang Jiung, Choi Suin, Lim Gayoung, Kim In Soo, Ohto Tatsuhiko, Maeda Seiya, Tada Hirokazu, Yoon Hyo Jae
Department of Chemistry, Korea University, Seoul, 02841, South Korea.
Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
Small. 2024 Feb;20(5):e2305997. doi: 10.1002/smll.202305997. Epub 2023 Sep 19.
Functionality in molecular electronics relies on inclusion of molecular orbital energy level within a transmission window. This can be achieved by designing the active molecule with accessible energy levels or by widening the window. While many studies have adopted the first approach, the latter is challenging because defects in the active molecular component cause low breakdown voltages. Here, it is shown that control over the packing structure of monolayer via supramolecular mixing transforms an inert molecule into a highly tunable rectifier. Binary mixed monolayer composed of alkanethiolates with and without carboxylic acid head group as a proof of concept is formed via a surface-exchange reaction. The monolayer withstands high voltages up to |4.5 V| and shows a dynamic rectification-external bias relationship in magnitude and polarity. Sub-highest occupied molecular orbital (HOMO) levels activated by the widened transmission window account for these observations. This work demonstrates that simple supramolecular mixing can imbue new electrical properties in electro-inactive organic molecules.
分子电子学中的功能依赖于在传输窗口内包含分子轨道能级。这可以通过设计具有可及能级的活性分子或拓宽窗口来实现。虽然许多研究采用了第一种方法，但后者具有挑战性，因为活性分子成分中的缺陷会导致低击穿电压。在此表明，通过超分子混合控制单层的堆积结构可将惰性分子转变为高度可调的整流器。作为概念验证，通过表面交换反应形成了由带有和不带有羧酸头基的链烷硫醇盐组成的二元混合单层。该单层能够承受高达|4.5 V|的高电压，并在幅度和极性上显示出动态整流-外部偏置关系。由拓宽的传输窗口激活的次最高占据分子轨道（HOMO）能级解释了这些观察结果。这项工作表明，简单的超分子混合可以赋予电惰性有机分子新的电学性质。
