A. El-Denglawey

Alternating current characterization of nano-Pt（II）octaethylporphyrin（PtOEP） thin film as a new organic semiconductor

Alternating current (AC) conductivity and dielectric properties of thermally evaporated Au/PtOEP/Au thin films are investigated each as a function of temperature (303 K–473 K) and frequency (50 Hz–5 MHz). The frequency dependence of AC conductivity follows the Jonscher universal dynamic law. The AC-activation energies are determined at different frequencies. It is found that the correlated barrier hopping (CBH) model is the dominant conduction mechanism. The variation of the frequency exponent s with temperature is analyzed in terms of the CBH model. Coulombic barrier height W m , hopping distance R ω , and the density of localized states N(E F) are valued at different frequencies. Dielectric constant e 1(ω,T) and dielectric loss e 2(ω,T) are discussed in terms of the dielectric polarization process. The dielectric modulus shows the non-Debye relaxation in the material. The extracted relaxation time by using the imaginary part of modulus (M) is found to follow the Arrhenius law.

Erratum to: The effect of long term aging on the structural and optical properties of nano metallo-tetraphenylporphine films

Thickness of 200 nm of NiTPP film is prepared by thermal evaporation technique under vacuum 10−6 torr as a candidate of nano metallo-tetraphenylporphine to study long aging. The prepared films are amorphous in nature while the aged samples were nano-structured with a crystallite size of 19 and 53 nm. An enhancement of crystallinity was seen after 6 months aging, while further aging showed structural stability. SEM micrograph confirms XRD results. Optical gap as well as optical constants and dispersion parameters are calculated; its values are increasing except the dispersion parameters are vice versa. The obtained changes are attributed to the enhancement of ordering because of aging time.