Self-assembled plasmonic templates produced by microwave annealing: applications to surface-enhanced Raman scattering

Abstract

Perhaps the simplest method for creating metal nanoparticles on a substrate is by driving their selfassembly with the thermal annealing of a thin metal film. By properly tuning the annealing parameters one hopes to discover a recipe that allows the pre-determined design of the nanoparticle (NP) arrangement. However, thermal treatment is known for detrimental effects and is not really the manufacturer's route of choice when it comes to largescale applications. An alternative method is the use of microwave annealing, a method that has never been applied for metal processing, due to the high reflectance of microwave radiation at the surface of a metal. However, in this work we challenge the widely used nanostructuring methods by proving microwave's annealing ability to produce plasmonic templates, out of extremely thin metal films, by simply using a domestic microwave oven apparatus. We show that this process is generic and independent of the deposition method used for the metal and we further quantify the suitability of these plasmonic templates for use in surface-enhanced Raman scattering applications.

Optical Properties and Plasmonic Performance of Titanium Nitride

“…This observation confirms and supports the great potential and perspectives of TiN plasmonic nanostructures reported recently [155]. The variation of the maximum value of ε 2 at the LSPR wavelength vs. the LSPR wavelength exhibits a distinct maximum above 500 nm (Figure 10, red symbols), in contrast to the monotonous increase of max-ε 2 with the LSPR wavelength observed for Ag nanoparticles [156]. Finally, the importance of E ps is also demonstrated for the case of LSPR, as well.…”

Self‐Assembled Silver–Gold Nanoisland Films on Glass for SERS Applications

“…Nevertheless, out‐diffused silver nanoisland film was several times tested with micro Raman spectroscopy of less concentrated R6G and biological analytes . The sensitivity achieved in our experiments is close to the reported ones for SERS‐active substrates under similar measurement conditions . SERS signal increase with depositing thin gold coating could be related with the rise of the cross‐section of the nanoisland–analyte interaction because of the increase of the film surface.…”

Broadband luminescence in defect-engineered electrochemically produced porous Si/ZnO nanostructures

“…pSi substrates were fabricated using an electroless etching process that requires three individual steps: Firstly, a 5–15 nm Ag thin film was deposited on top of a p -type Si (100) wafer (1–10 Ohm·cm) by magnetron sputtering; note that the use of sputtering for the deposition of silver is not essential, as similar silver ultrathin films can be deposited by a variety of vacuum-free techniques, such as electroless deposition 33 , 34 , gravure printing 35 , and inkjet printing 36 . Secondly, the Si/Ag structure was heated to 300 °C for 30 s, on a hot plate.…”

“…Secondly, the Si/Ag structure was heated to 300 °C for 30 s, on a hot plate. This step formed Ag nanoparticles (NPs) on top of the Si substrate due to dewetting of Ag 33 . Their size strongly depends on the initial thickness of the Ag thin film.…”