LIPSS for SERS: Metal coated direct laser written periodic nanostructures for surface enhanced raman spectroscopy

Date
2022-11-18
Advisor
Supervisor
Co-Advisor
Co-Supervisor
Instructor
Source Title
Advanced Optical Materials
Print ISSN
Electronic ISSN
2195-1071
Publisher
Wiley-VCH Verlag GmbH & Co. KGaA
Volume
10
Issue
22
Pages
2200233- 1 - 2200233- 11
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Series
Abstract

A novel method of fabricating large-area, low-cost surface-enhanced Raman spectroscopy (SERS) substrates is introduced which yields densely nanostructured surfaces utilizing laser-induced periodic surface structuring (LIPSS) of crystalline silicon (Si). Two different interaction regimes yield low spatial frequency (LSFL) and high spatial frequency (HSFL) LIPSS patterns. Nanostructuring of Si surface is followed by deposition of a thin noble metal layer to complete the fabrication procedure. A 50–70 nm thick Ag layer is shown to maximize the SERS performance. The SERS effect is attributed to the electromagnetic field enhancement originating from the nanoscale surface roughness of Si that can be controlled by LSFL and HSFL nature of the structure. The SERS substrates are found to be capable of detecting a Raman analyte down to 10−11 m. SERS performance of the Ag deposited substrates at 532, 660, and 785 nm excitation wavelengths is compared. Both LSFL and HSFL Si surfaces with 70 nm thick Ag are found to exhibit the strongest SERS under 660 nm excitation exhibiting Raman enhancement factors (EFs) as high as 109. The Raman EFs are calculated both by SERS spectra experimentally, and using finite-elements method simulation of the electric field enhancement where a good agreement is found.

Course
Other identifiers
Book Title
Keywords
High spatial frequency LIPSS, Laser-induced periodic surface structures, Low spatial frequency LIPSS, Surface enhanced Raman spectroscopy
Citation
Published Version (Please cite this version)