Effects of potassium dichromate on the structural, linear/nonlinear optical properties of the fabricated PVA/PVP polymeric blends: For optoelectronics

The role of thin films in the optical field has received increased attention across several disciplines. In this present work, the synthesis of composite films of different potassium dichromate (K₂Cr₂O₇)-doped Polyvinyl alcohol/Polyvinyl pyrrolidone (PVP/PVP) blend polymer was achieved using the solution casting method. According to XRD analysis, the semi-crystallinity nature of PVA/PVP was evaluated, where the primary peak intensity was also varied as the K₂Cr₂O₇ wt% increased. In contrast, FT-IR investigations illustrated a strong peak in all K₂Cr₂O₇: PVA/PVP films assigned to asymmetric stretching vibration (CH). An increment in the absorption spectra was enhanced with the high doping contents of K₂Cr₂O₇ on the PVA/PVP blend polymer, where vice versa was observed in the transmission spectra. Urbach, direct and indirect optical energies were obtained to be symmetrically decreased with increasing K₂Cr₂O₇ weight concentrations in the host PVA/PVP blend polymer. Based on the energy bandgap, seven empirical, theoretical relations were proposed to optimize the linear refractive index. An increase in the nonlinear optical parameters for the addressed polymers was observed with the wt% increase of K₂Cr₂O₇. The proposed polymeric films of K₂Cr₂O₇ with PVA/PVP would be a unique optical potential system for different technical applications in optoelectronics, optical filters, laser limiters, and biomedical laser.