Impact of DC nitrogen plasma on optical properties of PVA/Y2O3 nanocomposite

In this study, polyvinyl alcohol (PVA) polymer samples were prepared using the solution casting technique, while yttrium oxide (Y2O3) nanoparticles were prepared using microwave hydrothermal method. PVA doped with Y2O3 nanoparticles at concentrations of 0.1, 0.3 and 0.5 wt.%. The samples of 65 µm thickness were exposed to d.c. nitrogen plasma using cold conical cathode plasma source for 30 min. SEM analysis revealed noticeable changes in surface morphology after nitrogen plasma treatment, while EDX confirmed the presence and uniform distribution of Y2O3 nanoparticles within the PVA polymer. FTIR spectroscopy showed enhanced interaction between Y2O3 nanoparticles and PVA after nitrogen plasma exposure. Optical characterization indicated increased absorption for all samples, accompanied by a reduction in the direct optical band gap of the samples after nitrogen plasma treatment. Additionally, the extinction coefficient, refractive index and optical conductivity increased for both pristine PVA and PVA/Y2O3 nanocomposites. The average surface roughness measurements shown that both Y2O3 nanoparticles incorporation and nitrogen plasma treatment modified the surface morphology of the samples.