Self-assembled 3-dimensional arrays of Au@SiO2 core-shell nanoparticles for enhanced optical nonlinearities
Self-assembled 3-dimensional arrays of Au@SiO2 core-shell nanoparticles for enhanced optical nonlinearities
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DOI：
10.1016/j.susc.2005.02.011
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发表时间：
2005-04-01
期刊：
影响因子：
1.9
通讯作者：
Nogami, M
中科院分区：
文献类型：
--
作者：
Yang, Y;Hori, M;Nogami, M
采用基于层层自组装（LBL）技术的简单“一步”法制备了均匀的SiO2包覆的Au纳米粒子，并组装成了三维有序阵列.每一层薄膜都呈现出密集的Au@SiO2复合纳米粒子二维阵列，薄膜厚度可通过沉积循环次数控制。这些多层膜表现出高的复合纳米粒子的有效堆积密度（0.57）。这些阵列还表现出增强的三阶光学非线性响应和超快的响应时间。在532 nm处，七层阵列的三阶非线性光学极化率为1.7 × 10（-9）esu，响应时间为几皮秒。根据静电近似，通过在适合于核-壳纳米颗粒模型的边界条件下求解拉普拉斯方程，计算了光学非线性的增强，并且主要归因于局域电场效应。(c)2005 Elsevier B. V.保留所有权利。
Homogeneous SiO2 coated Au nanoparticles were prepared and assembled into densely-packed 3-dimensional arrays by a simple "one-step" route based on the layer-by-layer self-assembly (LBL) technique. Every layer of films exhibited densely packed 2-dimensional arrays of Au@SiO2 composite nanoparticles and the film thickness was controllable through the number of deposition cycles. These multilayer films exhibited high effective packing density of composite nanoparticles (0.57). Those arrays also exhibited enhanced third-order optical nonlinear responses and ultra-fast response times. The third-order nonlinear optical susceptibility of the seven layer arrays was estimated to be 1.7 x 10(-9) esu at 532 nm and the response time was as fast as several picoseconds. The enhancement of the optical non-linearity was calculated according to the electrostatic approximation by solution of Laplace's equation under the boundary conditions appropriate to the model of core-shell nanoparticles, and mainly attributed to localized electric-field effects. (c) 2005 Elsevier B.V. All rights reserved.