Polaron activation energy of nano porphyrin nickel(II) thin films

Abstract

5,10,15,20-Tetraphenyl-21H, 23H-porphyrin nickel(II), NiTPP films were prepared by thermal evaporation method of mother powder material. Electrical as well as thermo-electric properties were investigated for the as-deposited and annealed NiTPP films. The effect of NiTPP film thickness (160-460 nm) and isochronal annealing in temperature range (300-348 K) on DC electrical properties were studied. Both bulk resistivity and the mean free path were determined; their values are 1.38 9 10 5 X cm and 0.433 nm, respectively. The electrical conductivity exhibits intrinsic and extrinsic conduction. The values of activation energy in extrinsic and intrinsic regions are 0.204 and 1.12 eV, respectively. Mott's parameters were determined at low temperature. Seebeck coefficient indicates p-type conduction of NiTPP films. Carrier density, mobility and holes concentration were determined. Seebeck coefficient decreases with the increasing of temperature, while the conductivity increases with the increasing of temperature. The difference between the conductivity and the thermoelectric power activation energies was attributed to the potential barrier grain boundaries.

Influence of annealing temperature on structural and optical properties of nanocrystalline Platinum octaethylporphyrin (PtOEP) thin films

“…This observation may be attributed to rearrangements in the atomic structure which improves the crystallinity of the films [30]. The average crystallite size, D was calculated using the Scherrer's equation [31]: …”

“…During film deposition and post-annealing, there is a possibility for development of some strain and dislocation in the film. The dislocation density, d (the length of dislocation lines per unit volume) is evaluated from the relation [31]:…”

Silver Nanowires Network Film with Enhanced Crystallinity toward Mechano‐Electrically Sustainable Flexible‐Electrode

“…The crystallite grain size of the Ag NWs film can be determined using the Scherrer's formula as follow equation (Equation (2)). [ 21,22 ] ( D c : Crystalline size, S : Scherrer constant (order of unity), λ: Incident radiation wavelength, β hkl : Width of a strong peak at half‐maximum intensity (FWHM), θ hkl : Bragg diffraction angle)…”

“…In addition, as shown in Figure 3c, based on the calculated crystallite grain size (crystalline size) with Scherrer's formula (Equation (2)), the dislocation density (ρ D ) of Ag NWs can be calculated as follow equation (Equation (3)). [ 20,21 ] …”

“…The crystallite grain size of the Ag NWs film can be determined using the Scherrer's formula as follow equation (Equation 2). [21,22] In addition, as shown in Figure 3c, based on the calculated crystallite grain size (crystalline size) with Scherrer's formula (Equation 2), the dislocation density (ρ D ) of Ag NWs can be calculated as follow equation (Equation 3). [20,21]…”