Exploring the surface-enhanced Raman scattering (SERS) activity of gold nanostructures embedded around nanogaps at wafer scale: Simulations and experiments

Lafuente, Marta ; Muñoz, Pablo ; Berenschot, Erwin J.W. ; Tiggelaar, Roald M. ; Susarrey-Arce, Arturo ; Gutiérrez Rodrigo, Sergio ; Kooijman, Lucas J. ; García-Blanco, Sonia M. ; Mallada, Reyes (Universidad de Zaragoza) ; Pina, María P. (Universidad de Zaragoza) ; Tas, Niels R.

Resumen: A unique way of converting free space light into a local electromagnetic field in small spaces is via metallic nanostructuring. In this work fabrication, experimental characterization and simulation of surface-enhanced Raman scattering (SERS) active specimens based on Au nanostructures are discussed. We used displacement Talbot lithography (DTL) to fabricate silicon nano-wedge substrates with Au nanostructures embedded around their apices. After the ion beam etching process, a nanogap is introduced between two Au nanostructures templated over nano-wedges, yielding specimens with SERS characteristics. The Au nanostructures and the nanogaps have symmetric and asymmetric configurations with respect to the wedges. With this nanofabrication method, various wafer-scale specimens were fabricated with highly controllable nanogaps with a size in the order of 6 nm for symmetric gaps and 8 nm for asymmetric gaps. SERS characteristics of these specimens were analyzed experimentally by calculating their analytical enhancement factor (AEF). According to finite-difference time-domain (FDTD) simulations, the Raman enhancement arises at the narrow gap due to plasmonic resonances, yielding a maximum AEF of 6.9 × 106. The results highlight the SERS activity of the nanostructures and ultimately comply with reliable substrates for practical applications.

Idioma: Inglés

DOI: 10.1016/j.apmt.2023.101929

Año: 2023

Publicado en: Applied Materials Today 35 (2023), 101929 [12 pp.]
ISSN: 2352-9407

Financiación: info:eu-repo/grantAgreement/EC/H2020/883390/EU/Advanced Surface Enhanced Raman Spectroscopy (SERS) based technologies for gas and liquids sensING in the area of chemical protection/SERSing
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2019-108660RB-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)