Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Phys Rev Lett. 2012 Dec 14;109(24):247401. doi: 10.1103/PhysRevLett.109.247401. Epub 2012 Dec 12.
The optical response of metallic nanoparticle arrays is dominated by localized surface plasmon excitations and is the sum of individual particle contributions modified by interparticle coupling that depends on specific array geometry. We demonstrate a so far unexplored distinct oscillatory behavior of the plasmon peak position, full width at half maximum, and extinction efficiency in large area amorphous arrays of Au nanodisks, which depend on the minimum particle center-to-center distance in the array. Amorphous arrays exhibit short-range order and are completely random at long distances. In our theoretical analysis we introduce a film of dipoles approach, within the framework of the coupled dipole approximation, which describes the array as an average particle surrounded by a continuum of dipoles with surface densities determined by the pair correlation function of the array.
金属纳米粒子阵列的光学响应由局域表面等离激元激发主导，是单个粒子贡献的总和，通过取决于特定阵列几何形状的粒子间耦合进行修饰。我们在大面积非晶态 Au 纳米盘阵列中展示了迄今为止尚未探索到的等离子体峰位置、半峰全宽和消光效率的明显的振荡行为，这取决于阵列中最小的粒子中心到中心的距离。非晶态阵列在短程范围内具有有序性，而在长程范围内则完全是随机的。在我们的理论分析中，我们引入了偶极子薄膜方法，在偶极子耦合近似的框架内，将阵列描述为一个被偶极子连续体包围的平均粒子，其表面密度由偶极子的关联函数决定。
