TY - JOUR
T1 - Exploring the surface-enhanced Raman scattering (SERS) activity of gold nanostructures embedded around nanogaps at wafer scale
T2 - Simulations and experiments
AU - Lafuente, Marta
AU - Muñoz, Pablo
AU - Berenschot, Erwin J.W.
AU - Tiggelaar, Roald M.
AU - Susarrey-Arce, Arturo
AU - Rodrigo, Sergio G.
AU - Kooijman, Lucas J.
AU - García-Blanco, Sonia M.
AU - Mallada, Reyes
AU - Pina, María P.
AU - Tas, Niels R.
PY - 2023/12
Y1 - 2023/12
N2 - 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.
AB - 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.
KW - Ordered nano-wedges
KW - Size-controllable nanogaps
KW - FDTD simulations
KW - Ordered symmetric and asymmetric
KW - nanostructures
KW - Ion beam etching (IBE)
KW - Gold sputtering
KW - UT-Hybrid-D
UR - http://www.scopus.com/inward/record.url?scp=85170650749&partnerID=8YFLogxK
U2 - 10.1016/j.apmt.2023.101929
DO - 10.1016/j.apmt.2023.101929
M3 - Article
SN - 2352-9407
VL - 35
JO - Applied Materials Today
JF - Applied Materials Today
M1 - 101929
ER -