Abstract
Optical properties of the as-deposited and annealed films of 5, 10, 15, 20-Tetraphenyl-21H, 23H-Porphyrin nickel (II), (NiTPP) were investigated using spectrophotometric measurements of both transmittance and reflectance at normal incidence of light in the wavelength range, 200–1100 nm. The obtained data of refractive index, and absorption index, were used to estimate the type of transition and both optical and fundamental gaps. The normal dispersion (λ > 600 nm) of refractive index is discussed in terms of single oscillator model of Wemple-Didomenico, while the anomalous dispersion (λ < 600 nm) is discussed according to multi oscillator. The dispersion parameters; oscillator energy, dispersion energy, optical dielectric constant at higher frequency, lattice dielectric constant, and the ratio of carrier concentration to the effective mass N/m* were determined. The real part of the dielectric constant, the imaginary part of the dielectric constant, the loss factor, the volume and the surface energy loss functions were estimated and discussed.
► The valence band formed by the combination of the highest occupied molecular orbitals, HOMO. ► The lowest unoccupied molecular orbitals,LUMO contribute to the conduction band. ► Band theory used to describe electronic transitions in semiconductors. ► Optical gap and fundamental energy gap are simultaneously presented. ► The values of real part of the dielectric constant are higher than that of the imaginary part.