Photoconversion of Copper Flakes to Nanowires with Ultrashort Pulse Laser Irradiation
Photoconversion of Copper Flakes to Nanowires with Ultrashort Pulse Laser Irradiation
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DOI：
10.1021/cm062592b
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发表时间：
2007-02
影响因子：
8.6
通讯作者：
Y. Shimotsuma;T. Yuasa;Hidekazu Homma;M. Sakakura;Atsuo Nakao;K. Miura;K. Hirao;M. Kawasaki;J. Qiu;P. Kazansky
中科院分区：
文献类型：
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作者：
Y. Shimotsuma;T. Yuasa;Hidekazu Homma;M. Sakakura;Atsuo Nakao;K. Miura;K. Hirao;M. Kawasaki;J. Qiu;P. Kazansky
纳米级材料的尺寸和形状为许多物理和化学性质提供了重要的控制，包括电导率和导热率、发光性和催化活性。1胶体化学家已经获得了几种球形金属和半导体成分的优异受控纳米尺寸颗粒，从而发现了胶体纳米晶体中的量子尺寸效应。2然而，已经发现了各种自下而上的方法来制造各向异性形状的胶体纳米粒子，其中大多数解决方法都是基于热过程。另一方面，自上而下的方法已被开发用于生产金属和半导体纳米线、纳米带和纳米棱柱。3-5 特别是，从简化程序和多种材料的应用的角度来看，激光诱导烧蚀方法已成为越来越流行的纳米颗粒制造方法。6-11 在金属和半导体表面观察到由散射入射激光场与表面等离子体激元波之间的干涉引起的波纹结构。 (SPWs).11,12 然而，到目前为止，还没有观察到通过脉冲激光照射在胶体悬浮液中形成纳米线，并且其出现的机制尚未完全了解。我们最近报告了第一个实验证据，证明在飞秒钛蓝宝石激光器的单聚焦光束照射后，嵌入石英玻璃中的周期性纳米结构。 13 这种现象可以用入射激光场和生成的体电子等离子体波之间的干涉来解释，从而导致电子等离子体浓度的周期性调制和透明材料的结构变化。在这里，我们报告了通过超快脉冲激光照射从铜片到纳米线和纳米球形成的光转换的首次观察。这种现象根据特征形状提供了两种不同的表面等离子体共振。由于光场和 SPW 之间的干涉，观察到的直径为 50 nm 的铜纳米线从初始薄片中碎裂。除了基础科学的基本问题之外，它还可以在光学偏振控制、导电纳米材料和催化金属等领域得到应用。
The size and shape of nanoscale materials provide important control over many of the physics and chemical properties, including electric and thermal conductivity, luminescence, and catalytic activity.1 Colloidal chemists have obtained excellent controlled nanosized particles for several spherical metal and semiconductor compositions, which has led to the discovery of the quantum size effect in colloidal nanocrystals.2 However, various bottom-up approaches for making anisotropic-shaped colloidal nanoparticles have been found, with most of these solution methods being based on a thermal process. On the other hand, top-down approaches have been developed for producing metal and semiconductor nanowires, nanobelts, and nanoprisms.3-5 In particular, the laser-induced ablation method has become an increasingly popular approach for making nanoparticles from the viewpoint of the concise procedure and application of a variety of materials.6-11 The ripple structures have been observed on the surface of the metal and semiconductor caused by the interferences between the scattering incident laser field and the surface plasmon-polariton waves (SPWs).11,12 However, until now, there has been no observation of nanowire formation in a colloidal suspension by pulsed laser irradiation and the mechanism of its appearance has not been fully understood. We recently reported the first experimental evidence of the periodic nanostructures embedded in silica glass after irradiation by a single focused beam of a femtosecond Ti:sapphire laser.13 The phenomenon is interpreted in terms of interference between the incident laser light field and the generated bulk electron plasma waves, resulting in the periodic modulation of electron plasma concentration and the structural changes in transparent material. Here, we report the first observation of the photoconversion from copper flakes to nanowires and nanospheres formation via ultrafast pulse laser irradiation. This phenomenon has provided two distinct surface plasmon resonances based on the characteristic shape. The observed copper nanowires of 50 nm diameter are fragmented from the initial flakes as a result of the interference between the light field and the SPWs. Beyond the fundamental issues of basic science, applications are possible in the areas of an optical polarization control, an electroconductive nanomaterial, and a catalytic metal.