Effect of Pr₆O₁₁ rare-earth oxide on the structural characteristics and optical parameters of polyvinyl alcohol film

Praseodymium oxide (Pr₆O₁₁) was embedded in the polyvinyl alcohol (PVA) matrix with different contents for the first time, using the casting method for preparation. Combining rare earth oxides with a polymer matrix has gained a lot of interest in optical applications lately. The impact of Pr₆O₁₁ on the PVA’s morphology and bandgap energy was our interest in the present study. PVA’s structure and morphology were determined via X-ray diffraction (XRD), Raman, Fourier transform infrared (FTIR), and scanning electron microscope (SEM) techniques. The XRD showed the influence of Pr₆O₁₁ on the characteristic peak of the PVA, indicating the change in the PVA’s structure and producing a new one. FTIR and Raman analyses demonstrated the combination and interaction between the Pr₆O₁₁ nanoparticles and the functional groups of the PVA. The optical constants were investigated through the absorbance data recorded from the UV–Visible spectrophotometer. The PVA’s bandgap energy (direct/indirect) was reduced to 4.51/2.13 eV, and the refractive index increased to 2.0902 after adding 4 wt.% Pr₆O₁₁ nanoparticles. Other optical parameters were determined and showed an improvement with the additive of Pr₆O₁₁ to the PVA matrix. The obtained matrix showed promising characteristics for optical materials applications.