Fabrication of silver nanoisland films by pulsed laser deposition for surface-enhanced Raman spectroscopy

Abstract

The results of studies on the fabrication and characterization of silver nanoisland films (SNIFs) using pulsed laser deposition (PLD) and the evaluation of these films as potential surface-enhanced Raman scattering (SERS) substrates are reported. The SNIFs with thicknesses in a range of 4.7 ± 0.2 nm to 143.2 ± 0.2 nm were deposited under different conditions on silicon substrates. Size and morphology of the fabricated silver nanoislands mainly depend on the substrate temperature, and number and energy of the laser pulses. SERS properties of the fabricated films were evaluated by measuring SERS spectra of para-mercaptoaniline (pMA) molecules adsorbed on them. SERS enhancement factors are shown to depend on the SNIF morphology, which is modified by changes of the deposition conditions. The highest enhancement factor in the range of 105 was achieved for SNIFs that have oval and circular silver nanoislands with small distances between them.

Revisiting semicontinuous silver films as surface-enhanced Raman spectroscopy substrates

“…SSFs can be fabricated on large area planar substrates using electron beam (or thermal) PVD techniques, and thus are simple to prepare and rather inexpensive. Island type structures can be also fabricated using pulsed laser deposition [42]. The SSFs form when 5–10 nm (mass thickness corresponding to hypothetical continuous film) of silver is e-beam deposited on a proper adhesion layer (for example silicon dioxide) [43–44].…”

An overview of surface-enhanced Raman scattering substrates by pulsed laser deposition technique: fundamentals and applications

“…The background gas (e.g., N 2 and Ar) could also be used to slow the plume expansion. Moreover, the substrate temperature influences the kinetic energy of metallic NPs and results in the formation of a highly ordered substrate structure [ 72 ]. Additionally, the morphology of PLD substrate could strongly affect the surface morphology of metallic NPs.…”

“…The change of substrate temperature also affects the properties of formed metallic NPs; particularly, the size and number density of metallic NPs can be adjusted. Budner et al [ 72 ] reported the effect of parameters in the PLD process on the morphology and SERS enhancement property of Ag NP films. The effective SERS enhancement was reached by altering the laser fluence, number of laser pulses, and substrate temperature.…”

Optically and electrically driven nanoantennas

“…Here, several approaches to create low-cost, large-area SERS substrates that exhibit homogeneous Raman intensity enhancement are introduced. The substrates are based on quasi-hexagonally ordered gold particles prepared by block-copolymer micellar nanolithography and electroless deposition [41], or on dense silver island films created by pulsed laser deposition [42] or physical vapor deposition [43]. In [44], individual plasmonic nanotags are prepared by coating gold nanoparticle clusters with Raman reporters.…”