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In this current work, we report on the surface morphology of pure (ZnO) and metal doped (MZO, M = Cu, Fe and Cd) zinc oxide nanostructures grown by sol-gel spin coating route onto a glass substrate at room temperature and speed of 1,000 rpm. We also investigate the effect of spinning speed on the physical and surface properties of coated ZnO films. The doping ratios Cu/Zn, Fe/Zn, Cd/Zn were kept at 2% in the solution. Atomic force microscope (AFM) revealed that nano-grains change in shape and growth orientation as a result of metal content. Average of grains sizes were found to be 87, 122, 174 and 260 nm respectively for pure, Cu, Fe and Cd doped ZnO. Based on the histogram profile, the shape looks like Gaussian curve for the pure ZnO, and it changes considerably for the M-doped ZnO films. Parameters of surface are investigated such as distribution of heights, power spectrum density (Psd), Fourier transform (Ft) of the picture and surface roughness (Rms). Spinning speed influences the surface and physical properties of coated ZnO films. The optimum results, high transparency (~72%) and low resistivity (9 kWcm), have been obtained with an increase in speed.

The electrical conductivity, thermoelectric power, and metal-insulator-semiconductor diode properties of polyaniline prepared in ionic liquid (PANI) have been investigated. The electrical conductivity of the polyaniline increases exponentially with increasing temperature. The electrical conductivity value at 28 °C is 0.21 S/cm. The Seebeck coefficient of the PANI decreases with increasing temperature. The electrical conductivity and thermoelectric power results suggest that the PANI is a p-type semiconductor polymer. The Al/PANI Schottky diode was fabricated and is a metal-insulator-semiconductor type device. The ideality factor nand barrier height bvalues of the diode at 298 K were found to be 2.78 and 0.85 eV, respectively. The barrier inhomogeneities are a very important explanation of the higher values of the ideality factor. The Gaussian distribution function was suggested for describing barrier height inhomogeneities. The standard deviation of the barrier height distribution oindicates the presence of the interface inhomogeneities. The Bvalue obtained from C-Vmeasurement is higher than that of the Bvalue obtained I-Vmeasurements.

The thermal decomposition kinetics of [Co(bipy)(H2O)4](C4H4O4) · 4H2O was carried out by thermogravimetry (TG) and derivate thermogravimetry (DTG) analysis at four heating rates of 5, 8, 11 and 14 °C/min in nitrogen atmosphere. TG confirmed that thermal decomposition of the compound takes place in a single step. The kinetic parameters (activation energy, frequency factor, and activation entropy) were calculated using various forms of non-isothermal methods. The activation energy obtained by the Ozawa method is in agreement with the value determined by the Coats–Redfern technique. However, a much lower activation energy was obtained by the Kissinger method.

Poly(butylenes adipate) ionomers (PBAi) were synthesized using dimethyl 5-sulfoisophthalate sodium salt (DMSI) up to 5 mol% of diacid monomer. We have investigated electrical and dielectric properties of the ionomers to evaluate alternating current (AC) parameters such as impedance, conductance, dielectric constant, admittance, susceptance, dielectric loss, and resistance by an impedance spectroscopy. It is seen that the ionic conductances of the ionomers increase with increasing content of DMSI. The AC conductance for the ionomers was found to vary as ωs with the index s ≥ 1. A decrease in the relative dielectric constant of the ionomers is observed with the increase in the ionic content. The electrical relaxation in the dielectric spectra of the ionomers was not observed due to the orientation polarization of the dipoles. It is also observed that the tangent loss increases with the increase in the ionic content.

Poly(butylenes adipate) ionomers (PBAi) were synthesized using dimethyl 5‐sulfoisophthalate sodium salt (DMSI) up to 5 mol% of diacid monomer. We have investigated electrical and dielectric properties of the ionomers to evaluate alternating current (AC) parameters such as impedance, conductance, dielectric constant, admittance, susceptance, dielectric loss, and resistance by an impedance spectroscopy. It is seen that the ionic conductances of the ionomers increase with increasing content of DMSI. The AC conductance for the ionomers was found to vary as ωswith the index s≥ 1. A decrease in the relative dielectric constant of the ionomers is observed with the increase in the ionic content. The electrical relaxation in the dielectric spectra of the ionomers was not observed due to the orientation polarization of the dipoles. It is also observed that the tangent loss increases with the increase in the ionic content.

The electronic conductivity of poly[2-(2-hydroxybenzyliden hydrazino)thiazole-4-yl methyl methacrylate] bearing a thiazole ring, Schiff base, and hydroxyl group in its side chain and its Ni(II) complex were measured as functions of temperature and frequency. The electrical measurements show the semiconducting nature of the samples as their electrical conductivity increased with increased temperature. Also, the activation energies were below 2 eV, which places them in the semiconductor regime. The conduction mechanism in the samples is discussed. Although extrinsic conduction mechanism occurs in the polymer, intrinsic conduction mechanism take places in its metal complex. The optical absorption spectra were recorded at room temperature and the optical energy gaps of samples were determined by optical spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 741–746, 2003

The synthesis, characterization, physico-chemical and electrical properties of complexes of pyridine-2-carbaldehyde thiosemicarbazone (PTSC) with transition element cations are reported. The complexes [Fe(PTSC)2Cl2]Cl and [Ni(PTSC)2-(H2O)2]Cl2 were prepared. Molecular structures of these complexes were identified by using elemental analyses, FT-IR, UV-VIS, thermogravimetric and molar conductivity techniques. The structure, along with other physico-chemical studies, established that the complexes of PTSC were low-spin. The spectroscopic study of the compounds showed that the transition metal complexes had octahedral geometry. A spectrophotometric determination of nickel(II) with pyridine-2-carbaldehde thiosemicarbazone in methyl alcohol solution is proposed and the stability constants of the nickel(II) complex were determined by the Job method. The electrical conductivity of the compounds increases with elevated temperature. Their conductivities follows the order Ni>Fe. The calculated values of the activation energy of mobility, Eμ, suggests that conduction in the studied complexes takes place by a hopping mechanism, where one electron hops from one molecule to another.

ZnO/CdO and ZnO/NiO nanocomposite (NC) thin films were synthesized using co-precipitation by the sol-gel method. ZnO/CdO and ZnO/NiO are varied as volume ratio (ZnO/CdO: 2/1 mL and 2.5/0.5 mL; ZnO/NiO: 2/1 mL and 2.5/0.5 mL). The optical characteristics were analytically investigated using the transmittance, absorbance and reflectance data. While the band gap of the alloyed ZnO increases with decreasing CdO, it decreases with decreasing NiO. This is in line with the fact that the band gap of CdO is smaller than ZnO and the band gap of NiO is greater than that of ZnO. Such systems behave as semiconductor demonstrating the band gap engineering. ZnO–CdO/p-Si and ZnO–NiO/p-Si heterojunctions exhibit rectifying behavior and photodiode property, indicating an increase in current with increasing illumination in the case of reverse bias. The quantity-dependent photoresponse properties were examined using the current-voltage (I–V), transient photocurrent (I-t) and transient photocapacitance (C-t) measurements. Time-resolved photoresponse reveals that the photocurrent is related to the assumption of continuously distributed trap states in the band gap.