Oliva-Ramírez Manuel, Wang Dong, Flock Dominik, Rico Víctor, González-Elipe Agustín R, Schaaf Peter
Chair Materials for Electrical Engineering and Electronics, Institute of Materials Science and Engineering and Institute of Micro and Nanotechnologies MacroNano, TU Ilmenau, 98693 Ilmenau, Germany.
Institute of Materials Science of Seville (CSIC), Américo Vespucio 49, 41092 Seville, Spain.
ACS Appl Mater Interfaces. 2021 Mar 10;13(9):11385-11395. doi: 10.1021/acsami.0c19327. Epub 2021 Feb 16.
Solid-state dewetting (SSD) on patterned substrates is a straightforward method for fabricating ordered arrays of metallic nanoparticles on surfaces. However, a drawback of this procedure is that the patterning of substrates usually requires time-consuming and expensive two-dimensional (2D) fabrication methods. Nanostructured thin films deposited by oblique angle deposition (OAD) present at the surface a form of stochastically arranged periodic bundles of nanocolumns that might act as a patterned template for fabricating arrays of nanoparticles by SSD. In this work, we explore this concept and investigate the effect of three different types of OAD SiO thin films on the SSD of Au deposited on their surface. We demonstrate that the size and spatial distribution of the particles can be tailored through the surface morphology of these OAD film substrates. It has been found that the SSD of the evaporated Au layer gives rise to a bimodal size distribution of particles. A majority of them appeared as mesoparticles with sizes ≳100 nm and the rest as nanoparticles with ∼10 nm, respectively, located either on top of the nanocolumns following their lateral distribution (i.e., resulting from a patterning effect) or incorporated inside the open mesopores existing among them. Moreover, on the SiO-OAD thin films where interconnected nanocolumnar bundles arrange in the form of discrete motifs, the patterning effect gave rise to the formation of approximately one Au mesoparticle per motif, which is one of the assets of patterned SSD. The morphological, optical (i.e., plasmon resonance), and crystalline structural characteristics of Au mesoparticles suggest that the interplay between a discontinuous nanocolumnar surface acting as a template and the poor adhesion of Au onto SiO are key factors for the observed template effect controlling the SSD on the surface of OAD thin films.
在图案化衬底上进行固态去湿（SSD）是在表面制备有序金属纳米颗粒阵列的一种直接方法。然而，该工艺的一个缺点是衬底的图案化通常需要耗时且昂贵的二维（2D）制造方法。通过倾斜角沉积（OAD）沉积的纳米结构薄膜在表面呈现出一种随机排列的纳米柱周期性束的形式，这可能作为通过SSD制造纳米颗粒阵列的图案化模板。在这项工作中，我们探索了这一概念，并研究了三种不同类型的OAD SiO薄膜对沉积在其表面的Au的SSD的影响。我们证明，可以通过这些OAD薄膜衬底的表面形态来调整颗粒的尺寸和空间分布。已经发现，蒸发的Au层的SSD会产生双峰尺寸分布的颗粒。其中大多数表现为尺寸≳100 nm的中颗粒，其余为尺寸约为10 nm的纳米颗粒，它们分别位于纳米柱顶部并遵循其横向分布（即由图案化效应产生）或并入其中存在的开放中孔内。此外，在相互连接的纳米柱束以离散图案形式排列的SiO - OAD薄膜上，图案化效应导致每个图案形成大约一个Au中颗粒，这是图案化SSD的优点之一。Au中颗粒的形态、光学（即等离子体共振）和晶体结构特征表明，作为模板的不连续纳米柱表面与Au与SiO之间较差的附着力之间的相互作用是控制OAD薄膜表面SSD的观察到的模板效应的关键因素。
