The Effects of Thermal Annealing and Postirradiation on Silver Nanoparticle Films Fabricated by Pulsed Laser Deposition in the Flowless Open Air

Abstract

Herein, Ag nanoparticle (NP) films are fabricated by pulsed laser deposition technique in the flowless atmospheric air. A Q‐switched Nd:YAG pulsed laser beam is used for the ablation process. The fabricated NP films are postirradiated by the pulsed laser beam. In addition, as‐deposited NP films are annealed in argon gas flow ambient for 45 min at different temperatures (250, 350, and 450 °C), and also annealed at 450 °C for 15, 30, and 45 min. The characteristics of fabricated NP films are investigated after postirradiating by pulsed laser beam, and thermal annealing in Ar gas flow. UV–vis absorption spectroscopy is utilized to provide surface plasmon resonance (SPR) characteristics of films. The results show that thermal annealing can lead to strong enhancement, and also narrowing of the SPR spectrum. The results of field emission scanning electron microscopy and atomic force microscopy show that the annealing and postirradiation processes can influence the NPs size and film structure. As an application, the fabricated film is utilized for surface‐enhanced Raman spectroscopy (SERS) using a 10−6 molar aqueous solution of Rhodamine 6G. The SERS results indicate that the annealed NP films become more sensitive than the as‐deposited films.