Open AccessGold-coated AFM tips for tip-enhanced Raman spectroscopy: theoretical calculation and experimental demonstration
Author(s) -
Lingyan Meng,
Teng-Xiang Huang,
Xiang Wang,
Shu Chen,
Zhilin Yang,
Bin Ren
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.013804
Subject(s) - materials science , raman spectroscopy , substrate (aquarium) , optics , atomic force microscopy , excitation , image resolution , spectroscopy , laser , optoelectronics , microscopy , nanotechnology , oceanography , physics , electrical engineering , engineering , quantum mechanics , geology
The optimal gold-coated atomic force microscopy (AFM) tip-substrate system for tip-enhanced Raman spectroscopy (TERS) was designed theoretically and demonstrated experimentally. By optimizing the tip, excitation laser, and the substrate, the TERS enhancement factor can be tuned to as high as 9 orders of magnitude, and the spatial resolution could be down to 5 nm. Preliminary experimental results for AFM tips coated with gold layer of different thicknesses reveal that the maximum enhancement can be achieved when the thickness is about 60-80 nm, which is in good agreement with the theoretical prediction. Our results not only provide a deep understanding of the underlying physical mechanism of AFM tip-based TERS, but also guide the rational construction of a working AFM-TERS system with a high efficiency.