Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
Center for Electron Nanoscopy, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
ACS Nano. 2016 Feb 23;10(2):2871-9. doi: 10.1021/acsnano.5b08057. Epub 2016 Feb 5.
Mixing different elements at the nanoscale to obtain alloy nanostructures with fine-tuned physical and chemical properties offers appealing opportunities for nanotechnology and nanoscience. However, despite widespread successful application of alloy nanoparticles made by colloidal synthesis in heterogeneous catalysis, nanoalloy systems have been used very rarely in solid-state devices and nanoplasmonics-related applications. One reason is that such applications require integration in arrays on a surface with compelling demands on nanoparticle arrangement, uniformity in surface coverage, and optimization of the surface density. These cannot be fulfilled even using state-of-the-art self-assembly strategies of colloids. As a solution, we present here a generic bottom-up nanolithography-compatible fabrication approach for large-area arrays of alloy nanoparticles on surfaces. To illustrate the concept, we focus on Au-based binary and ternary alloy systems with Ag, Cu, and Pd, due to their high relevance for nanoplasmonics and complete miscibility, and characterize their optical properties. Moreover, as an example for the relevance of the obtained materials for integration in devices, we demonstrate the superior and hysteresis-free plasmonic hydrogen-sensing performance of the AuPd alloy nanoparticle system.
将不同元素混合在纳米尺度上，以获得具有精细调控物理和化学性质的合金纳米结构，为纳米技术和纳米科学提供了诱人的机会。然而，尽管胶体合成制备的合金纳米粒子在多相催化中得到了广泛的成功应用，但纳米合金体系在固态器件和与纳米等离子体学相关的应用中却很少使用。原因之一是这些应用需要在表面上进行集成阵列，这对纳米粒子排列、表面覆盖率的均匀性以及表面密度的优化提出了极高的要求，即使使用最先进的胶体自组装策略也无法满足这些要求。作为一种解决方案，我们在这里提出了一种通用的自下而上的纳米光刻兼容的制造方法，用于在表面上制造大面积的合金纳米粒子阵列。为了说明这一概念，我们重点关注基于 Au 的二元和三元合金体系，包括 Ag、Cu 和 Pd，因为它们与纳米等离子体学密切相关且完全混溶，并对它们的光学性质进行了表征。此外，作为所获得的材料在器件集成方面的相关性的一个例子，我们展示了 AuPd 合金纳米粒子体系优越且无迟滞的等离子体氢传感性能。
