Topological, morphological and optical properties of Gamma irradiated Ni (II) tetraphenyl porphyrin thin films

Thermal evaporation technique was used to prepare NiTPP Thin films at room temperature. The prepared films were divided into two groups; the first group was as-deposited films, and the second group was irradiated in gamma cell type 60Co source at room temperature with total absorbed dose of 150 kGy in air. All films were identified by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) before and after exposed to gamma radiation. The spectrophotometric measurement of transmittance and reflectance were used to investigate the optical properties at normal incidence of light in the wavelength range 200–2500 nm for as-deposited and gamma-irradiated films. Optical constants (refractive index n, and absorption index k) of as-deposited and irradiated films have been obtained in the wavelength range 200–2500 nm for all the samples. The single oscillator energy (Eo), the dispersion energy (Ed), the high frequency dielectric constant (ε∞), the lattice dielectric constant (εL) and the ratio of the free charge carrier concentration to the effective mass (N/m⁎) were estimated for each group. The absorption analysis has been also performed to determine the type of electronic transition and the optical energy gap.