Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore.
Small. 2012 Aug 20;8(16):2548-54. doi: 10.1002/smll.201200576. Epub 2012 Jun 6.
A highly ordered particle-in-bowl (PIB) nanostructure array is designed and fabricated to achieve large field enhancement for the surface-enhanced Raman scattering (SERS) application. This new type of PIB structure is composed of an Ag particle located at the bottom of an Au bowl, and the two are separated by a precisely controlled nanoscale dielectric layer. The fabrication of the PIB structure is based on the self-assembly of polystyrene spheres and atomic layer deposition (ALD), which allows good control of the metal particle size and gap distance, as well as large-scale ordering. Numerical simulation reveals a high enhancement of the local field at the nanogaps. The SERS performance of the PIB arrays, and the effects of the Ag particle size and the ALD dielectric layer thickness are characterized, results of which are in reasonable agreement with simulation. With Rhodmaine 6G as the probe molecule, the spatially averaged SERS enhancement factor is on the order of 3.8 × 10(7) and the local field enhancement from simulation can be up to 10(8) .
设计并制备了一种高度有序的粒子在碗中（PIB）纳米结构阵列，以实现用于表面增强拉曼散射（SERS）应用的大场增强。这种新型的 PIB 结构由位于 Au 碗底部的 Ag 粒子和通过精确控制的纳米级介电层隔开的两个部分组成。PIB 结构的制备基于聚苯乙烯球和原子层沉积（ALD）的自组装，这允许对金属颗粒尺寸和间隙距离以及大规模有序性进行良好的控制。数值模拟揭示了纳米间隙处局部场的高增强。对 PIB 阵列的 SERS 性能以及 Ag 颗粒尺寸和 ALD 介电层厚度的影响进行了表征，结果与模拟结果吻合良好。使用 Rhodmaine 6G 作为探针分子，空间平均 SERS 增强因子约为 3.8×10(7)，并且模拟的局部场增强可高达 10(8)。
