Site-selective integration of monolayer-protected inorganic nanoparticles onto surface monolayer templates by a solvent-induced lift-off process.
Site-selective integration of monolayer-protected inorganic nanoparticles onto surface monolayer templates by a solvent-induced lift-off process.
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DOI：
10.1002/smll.200600171
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发表时间：
2006-10
期刊：
影响因子：
13.3
通讯作者：
K. Akamatsu;S. Samitsu;T. Tsuruoka;J. Hasegawa;H. Nawafune
中科院分区：
文献类型：
--
作者：
K. Akamatsu;S. Samitsu;T. Tsuruoka;J. Hasegawa;H. Nawafune
由金属和/或半导体纳米颗粒组成的有机/无机混合纳米复合材料的薄膜已经成为最近深入研究下一代电子、光子和磁性纳米器件制造的主题。[1-9]迄今为止，大多数的努力都集中在这些纳米结构的薄膜和多层的制造上。[10-13]对于许多应用，无机纳米粒子应功能性地集成到器件中以形成微图案，这通常需要控制纳米粒子之间以及纳米粒子与衬底表面之间的相互作用。最近的几项研究取得了进展，提供了在感兴趣的基底上沉积和生长无机纳米颗粒的方法。这些方法包括Au [14]和CdSe/CdS核/壳纳米颗粒的预成型膜的微图案化，[15]通过静电相互作用对CdSe/ZnS纳米颗粒的预先设计的表面模板进行位点选择性固定，[16-18]以及通过共价连接Au簇[19]和CdSe/ZnS纳米颗粒。[20]也有报道通过软光刻直接沉积无机纳米颗粒，例如CdS/树枝状聚合物纳米复合物[21]和g-Fe 2 O3纳米颗粒[22]。为了生成用于未来微电子和纳米电子器件的纳米复合材料图案，开发一种新的、简单地在衬底上制造纳米复合材料电路的位置选择性沉积策略仍然是一个巨大的挑战。此外，基于溶液的低能量工艺将可用于装置的低成本制造。在此，我们提出了一个简单的方法，以及一个独特的程序，用于制造纳米颗粒膜图案组成的单层保护的无机纳米粒子到表面单层模板。通过颗粒膜的选择性剥离实现了位点选择性整合。这被认为是由于溶剂渗透到膜和基底上的单层之间的界面中（基于溶剂和单层的极性）而实现的（图1）。该方法被描述为一种基于减法的策略，并提供了一种有效的方法，通过简单的基于溶液的processing.Gold纳米粒子的单层保护的无机nanoparticles的理想集成被保护的11-mercaptodendecanoic acid（MUA）被用作纳米复合材料的模型构建块，并根据修改的两相法制备。[23，24] MUA保护的Au纳米粒子（直径为2.4 nm）可溶于极性有机溶剂，但不溶于中性水。硅晶片衬底上的模板单层图案与表面氧化层（100 nm）通过化学气相沉积（CVD），然后真空紫外（VUV）光刻，[25]使用铜网格作为光掩模制备。因此产生十八烷基三甲氧基硅烷自组装单层（OTS-SAM，疏水性）和带有羟基的氧化硅表面（亲水性）（图1）。
Thin films of organic/inorganic hybrid nanocomposites composed of metal and/or semiconductor nanoparticles have been the subject of recent intensive research into the fabrication of the next-generation electronic, photonic, and magnetic nanodevices.[1–9] The majority of efforts thus far have focused on the fabrication of thin films and multilayers of these nanostructures.[10–13] For many applications, inorganic nanoparticles should be functionally integrated into devices to form micropatterns, which usually requires control over interactions between nanoparticles, and between a nanoparticle and a substrate surface. Several recent investigations have made advances that provide methods for the deposition and growth of inorganic nanoparticles on the substrates of interest. These approaches include micropatterning of preformed films of Au [14] and CdSe/CdS core/shell nanoparticles,[15] site-selective immobilization through electrostatic interaction on predesigned surface templates for CdSe/ZnS nanoparticles,[16–18] and through covalent linking for Au clusters [19] and CdSe/ZnS nanoparticles.[20] There are also reports of the direct deposition of inorganic nanoparticles, for example, CdS/dendrimer nanocomposites [21] and g-Fe2O3 nanoparticles [22] via soft lithography. In order to generate patterns of nanocomposites for future micro-and nanoelectronic devices, development of a novel, site-selective deposition strategy that simply fabricates nanocomposite circuits on the substrates still remains a great challenge. Further, solution-based, low-energy processes would be useful for the low-cost fabrication of devices. Herein, we present a simple approach as well as a unique procedure for fabricating nanogranular film patterns composed of monolayer-protected inorganic nanoparticles onto surface monolayer templates. Site-selective integration was achieved by selective lift-off of the granular films. This is thought to be accomplished due to penetration of solvents into the interface between the films and the monolayers on the substrates based on the polarity of the solvents and monolayers (Figure 1). The process is described as a subtractive-based strategy, and provides effective methodology for desirable integration of monolayer-protected inorganic nanoparticles through simple solution-based processing.Gold nanoparticles protected by 11-mercaptoundecanoic acid (MUA) were used as model building blocks for nanocomposites and prepared according to the modified twophase method.[23, 24] MUA-protected Au nanoparticles (2.4 nm in diameter) were prepared, which were soluble in polar organic solvents, but were insoluble in neutral water. Template monolayer patterns on Si wafer substrates with a surface oxide layer (100nm) were prepared by chemical vapor deposition (CVD), followed by vacuum ultraviolet (VUV) lithography,[25] using a copper mesh grid as a photomask. Octadecyltrimethoxysilane self-assembled monolayers (OTS-SAMs, hydrophobic) and a silicon oxide surface bearing hydroxyl groups (hydrophilic) were thus produced (Figure 1).