Optical Properties of Polymeric/Selenium-Nobel Metal Nanocomposites Synthesized by Pulsed Laser Ablation

Objectives A novel synthesis method of polyvinyl alcohol/selenium-silver-gold (PVA/Se-Ag-Au), (PVA/Se), (PVA/Se-Ag), and (PVA/Se-Au) nanocomposite films are reported. The method incorporates, for the first time, two or more individually laser-formed nanoparticles (NPs) into PVA. Material and Methods The method involves the simple mixing of three distinct noble/semiconductor NPs synthesized by pulsed laser ablation in liquid (PLAL), a green method that yields ligand-free NPs in just 10 min. Results Firstly, the PLAL solutions are characterized using transmission electron microscope (TEM) and UV-visible spectroscopy, yielding average sizes of 92, 28.6, and 9.2 nm for Se, Ag, and Au, respectively. The PyMieLab software is utilized to calculate the optical properties of the individual NPs under study; the more spherical and compact the NPs, the greater the agreement with experimental data. Secondly, the films made using the drop-casting method exhibit UV-visible spectra with the peaks shifting from 403 and 526 nm for the Se-Ag-Au system to 401 and 556 nm for the polymeric system. Fourier-transform infrared (FTIR) spectroscopy technique confirms shifts in peak positions and the appearance of new peaks, indicating the interaction between PVA and NPs. Conclusion Tauc-plot studies show that the bandgap of the materials is tuned before and after incorporation with the polymer, increasing it by more than 0.5 eV in some cases, thereby enhancing their application in photonic devices.