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PSSE (Scientific Section)
STRUCTURE-PROPERTY RELATIONSHIP AND PLASMON-ENHANCED PHOTOLUMINESCENCE IN Ag@Ag2O CORE-SHELL NANOPARTICLE THIN FILMS
Meri Sokolovska1, Rola Moussa2, Ljupcho Pejov1, Vlado Lazarov2, Biljana Pejova1
e-mail: merisokolovska@yahoo.com
1Institute of Chemistry, Faculty of Natural Sciences and Mathematics,
SS Cyril and Methodius University, Skopje, Macedonia
2School of Physics Engineering and Technology, University of York, York, YO10 5DD, UK
Silver/silver oxide (Ag@Ag2O) core-shell nanoparticles have attracted considerable attention due to their unique combination of plasmonic and semiconducting properties, making them promising materials for applications in sensing, photocatalysis and optoelectronics. In this work, Ag@Ag2O NP thin films were synthesized and systematically characterized to investigate the relationship between their structural, morphological, optical and photoluminescence properties.
The crystal structure and phase composition were examined by X-ray diffraction (XRD) and selected area electron diffraction (SAED), confirming the coexistence of metallic Ag and Ag2O phases. Raman spectroscopy revealed characteristic vibrational modes associated with Ag2O and provided additional evidence of the composite Ag/Ag2O structure. The enhanced Raman response observed from the nanostructured thin films indicates the presence of strong localized electromagnetic fields generated by the Ag component, highlighting the potential of the films as Surface-Enhanced Raman Scattering (SERS) active substrates. Transmission electron microscopy (TEM) revealed the formation of nanoparticles with a distinct core-shell architecture, while scanning electron microscopy (SEM) provided information on particle morphology. Atomic force microscopy (AFM) was employed to analyse the surface topography and nanoscale roughness of deposited NP thin films.
The optical properties were investigated using UV-Vis spectroscopy, revealing a pronounced localized surface plasmon resonance (LSPR) associated with the Ag core. Photoluminescence measurements demonstrated a significant enhancement of the emission intensity compared to pure Ag2O nanostructures. The observed enhancement is attributed to the coupling between the semiconductor excitonic transitions of Ag2O shell and the localized plasmonic field generated by the Ag core.
The results provide valuable insights into the structure-property relationships governing the optical response of Ag@Ag2O nanostructures and highlight their potential for plasmon-enhanced photonic, sensing and SERS applications.
Keywords: Ag@Ag2O nanoparticles, core-shell nanostructures, plasmonics, SERS substrates, photoluminescence enhancement, XRD, TEM, SEM, AFM.