PRISA 1.0 software written in Python determines optical properties viz. refractive index (n), extinction co-efficient (k), absorption co-efficient (α), band gap (Eg), dispersion energy (Ed), and oscillator energy(E0) as well as thickness (d) of thin films deposited on a transparent substrate from their measured transmission spectrum only.
Swanepoel method is used for determining n, k and d. The value of Ed and E0 are derived using single oscillator model.
Absorption co-efficient (α) in the strong absorption region is derived using Connell and Lewis method.
Optical bandgap (Eg) is derived from α using Tauc plot.