This study reports on the optical parameters of MoO3–V2O5–PbO films. The measured transmittance spectra in
the spectral range 300–2500 nm was used for precise calculations of the complex index of refraction (real (n) and
imaginary (k) parts) as well as the film thicknesses. With the addition of MoO3, a blue shift of the absorption
edge was represented while the index of refraction (n) was decreased. The decrease of the index of refraction was
discussed in terms of the dispersion model. A good correlation between the bulk modulus Kop, the optical band
gap Eg and the index of refraction was observed. With the help of Kop, Eg and n values, the electronic polarizability
has been calculated for the films under study. The results well discussed in terms of the density, electronegativity
and polarizability changes due to the addition of MoO3 content.