Structural, optical and electrical, properties of NiTPP Thin films

The structural properties of NiTPP thin films were investigated using (DTA) (TGA), (XRD), (SEM), (TEM) and (FTIR). These investigations were carried out to identify the crystalline state, crystal system, lattice constants, the crystallite size and the dislocation density. The result of this procedures indicated that as-deposited thin films have amorphous nature but for annealed thin films have polycrystalline nature. Optical properties of the as- deposited and annealed thin films of NiTPP were investigated by using spectrophotomeric measurements of T(¿) and R(¿). The obtained data of refractive index n and absorption index k were used to estimate the type of transition and optical and fundamental gaps. The normal dispersion of refractive index n is discussed in terms of single oscillator model. The conduction mechanism at lower temperature range (300-330 K) is explained in terms of hopping through a band of localized and Mott parameters were calculated, while at higher temperature range (330 - 450 K) the band conduction is valid. The positive Seebeck coefficient, S, measurements indicated that NiTPP films behave as p-type semiconductor.