  Tin sulphide thin films of p-type conductivity were grown on glass
substrates. The refractive index of the as grown films, calculated using both
Transmission and ellipsometry data were found to follow the Sellmeier
dispersion model. The improvement in the dispersion data obtained using
ellipsometry was validated by Wemple-Dedomenico (WDD) single oscillator model
fitting. The optical properties of the films were found to be closely related
to the structural properties of the films. The band-gap, its spread and
appearance of defect levels within the band-gap intimately controls the
refractive index of the films.
