Chen Ningyue, Li Shuwei, Zhao Peng, Liu Ran, Xie Yu, Lin Jin-Liang, Nijhuis Christian A, Xu Bingqian, Zhang Liang, Xu Huaping, Li Yuan
Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China.
Center for Combustion Energy, Tsinghua University, Beijing 100084, China.
Sci Adv. 2023 Oct 20;9(42):eadh3412. doi: 10.1126/sciadv.adh3412. Epub 2023 Oct 18.
The molecular electronic devices based on self-assembled monolayer (SAM) on metal surfaces demonstrate novel electronic functions for device minimization yet are unable to realize in practical applications, due to their instability against oxidation of the sulfur-metal bond. This paper describes an alternative to the thiolate anchoring group to form stable SAMs on gold by selenides anchoring group. Because of the formation of strong selenium-gold bonds, these stable SAMs allow us to incorporate them in molecular tunnel junctions to yield extremely stable junctions for over 200 days. A detailed structural characterization supported by spectroscopy and first-principles modeling shows that the oxidation process is much slower with the selenium-gold bond than the sulfur-gold bond, and the selenium-gold bond is strong enough to avoid bond breaking even when it is eventually oxidized. This proof of concept demonstrates that the extraordinarily stable SAMs derived from selenides are useful for long-lived molecular electronic devices and can possibly become important in many air-stable applications involving SAMs.
基于金属表面自组装单分子层（SAM）的分子电子器件展现出了用于器件小型化的新型电子功能，但由于其硫-金属键对氧化不稳定，无法在实际应用中实现。本文描述了一种替代硫醇盐锚定基团的方法，即通过硒化物锚定基团在金表面形成稳定的自组装单分子层。由于形成了强硒-金键，这些稳定的自组装单分子层使我们能够将它们纳入分子隧道结中，从而产生超过200天的极其稳定的结。光谱学和第一性原理建模支持的详细结构表征表明，硒-金键的氧化过程比硫-金键慢得多，并且即使最终被氧化，硒-金键也足够强以避免键断裂。这一概念验证表明，源自硒化物的极其稳定的自组装单分子层对于长寿命分子电子器件是有用的，并且在许多涉及自组装单分子层的空气稳定应用中可能变得很重要。
