Belić Domagoj, Shawrav Mostafa M, Gavagnin Marco, Stöger-Pollach Michael, Wanzenboeck Heinz D, Bertagnolli Emmerich
Institute of Solid State Electronics, Vienna University of Technology , Floragasse 7/1, A-1040 Vienna, Austria.
ACS Appl Mater Interfaces. 2015 Feb 4;7(4):2467-79. doi: 10.1021/am507327y. Epub 2015 Jan 21.
Three-dimensional gold (Au) nanostructures offer promise in nanoplasmonics, biomedical applications, electrochemical sensing and as contacts for carbon-based electronics. Direct-write techniques such as focused-electron-beam-induced deposition (FEBID) can provide such precisely patterned nanostructures. Unfortunately, FEBID Au traditionally suffers from a high nonmetallic content and cannot meet the purity requirements for these applications. Here we report exceptionally pure pristine FEBID Au nanostructures comprising submicrometer-large monocrystalline Au sections. On the basis of high-resolution transmission electron microscopy results and Monte Carlo simulations of electron trajectories in the deposited nanostructures, we propose a curing mechanism that elucidates the observed phenomena. The in situ focused-electron-beam-induced curing mechanism was supported by postdeposition ex situ curing and, in combination with oxygen plasma cleaning, is utilized as a straightforward purification method for planar FEBID structures. This work paves the way for the application of FEBID Au nanostructures in a new generation of biosensors and plasmonic nanodevices.
三维金（Au）纳米结构在纳米等离子体学、生物医学应用、电化学传感以及作为碳基电子学的接触材料方面展现出了应用前景。诸如聚焦电子束诱导沉积（FEBID）等直写技术能够提供这种精确图案化的纳米结构。不幸的是，传统的FEBID金存在高非金属含量的问题，无法满足这些应用的纯度要求。在此，我们报道了由亚微米级大的单晶金部分组成的纯度极高的原始FEBID金纳米结构。基于高分辨率透射电子显微镜结果以及对沉积纳米结构中电子轨迹的蒙特卡罗模拟，我们提出了一种固化机制来解释所观察到的现象。原位聚焦电子束诱导固化机制得到了沉积后异位固化的支持，并且与氧等离子体清洗相结合，被用作平面FEBID结构的一种直接纯化方法。这项工作为FEBID金纳米结构在新一代生物传感器和等离子体纳米器件中的应用铺平了道路。
