大面积纳米间隙等离子体激元共振腔阵列在等离子体学中的应用。

Large-area nanogap plasmon resonator arrays for plasmonics applications.

机构信息

BIOS Lab on a Chip Group, MESA+ Institute for Nanotechnology, University of Twente, Hallenweg 15, Enschede, 7500 AE, The Netherlands.

出版信息

Nanoscale. 2012 Aug 7;4(15):4712-8. doi: 10.1039/c2nr30576c. Epub 2012 Jun 29.

DOI:10.1039/c2nr30576c

PMID:22743701

Abstract

Large-area (∼8000 mm(2)) Au nanogap plasmon resonator array substrates manufactured using maskless laser interference lithography (LIL) with high uniformity are presented. The periodically spaced subwavelength nanogap arrays are formed between adjacent nanopyramid (NPy) structures with precisely defined pitch and high length density (∼1 km cm(-2)), and are ideally suited as scattering sites for surface enhanced Raman scattering (SERS), as well as refractive index sensing. The two-dimensional grid arrangement of NPy structures renders the excitation of the plasmon resonators minimally dependent on the incident polarization. The SERS average enhancement factor (AEF) has been characterized using over 30 000 individual measurements of benzenethiol (BT) chemisorbed on the Au NPy surfaces. From the 1(a(1)), β(CCC) + ν(CS) ring mode (1074 cm(-1)) of BT on surfaces with pitch λ(g) = 200 nm, AEF = 0.8 × 10(6) and for surfaces with λ(g) = 500 nm, AEF = 0.3 × 10(7) from over 99% of the imaged spots. Maximum AEFs > 10(8) have been measured in both cases.

摘要

采用无掩模激光干涉光刻（LIL）制造的大面积（约 8000mm²）金纳米间隙等离子体共振器阵列衬底具有高度均匀性。周期性间隔的亚波长纳米间隙阵列形成于具有精确定义的间距和高密度（约 1kmcm⁻²）的相邻纳米金字塔（NPy）结构之间，非常适合作为表面增强拉曼散射（SERS）以及折射率传感的散射点。NPy 结构的二维网格排列使得等离子体共振器的激发对入射偏振最小化依赖。使用超过 30000 个苯硫醇（BT）化学吸附在 Au NPy 表面的个体测量，对 SERS 平均增强因子（AEF）进行了表征。从表面上的 1(a(1))，β(CCC) + ν(CS)环模式（1074cm⁻¹）的 BT，在 λ(g)=200nm 的表面上，AEF=0.8×10⁶，而在 λ(g)=500nm 的表面上，AEF=0.3×10⁷，超过 99%的成像点。在这两种情况下，都测量到了超过 10⁸的最大 AEF。