The films prepared by casting method with different percentages of nano yttrium oxide (0, 3, 6, 9 and 12) wt%, where optical microscope images show the yttrium nanoparticles form a continuous network inside the polymers when the proportion of (12 wt%). FTIR spectra shows
shift in peak position as well as change in shape and intensity, comparing with pure (PVA-PVP) films, this indicates decoupling between the corresponding vibrations of two polymers and yttrium nanoparticles, and we noted that there is a decrease in transmittance at increasing the proportion
of yttrium oxide nanoparticles. Scanning electron microscopy shows the surface morphology of the (PVA-PVP-Y2O3) films many aggregates or chunks randomly distributed on the top surface, homogeneous and coherent. The absorbance increases with increase the weight percentages
of nano yttrium oxide. The absorption coefficient, extinction coefficient, refractive index, real and imaginary parts of dielectric constants and optical conductivity are increasing with increase the weight percentages of yttrium oxide. The energy band gap decreases with increasing the weight
percentages of yttrium oxide. The D.C electrical conductivity increase by increasing yttrium oxide concentrations and temperature. The activation energy decreases by increasing yttrium oxide concentrations. The resistance of the sensor decreased as humidity increased.