Search

Zn1-xAxO (A: Fe, Ni, Co and Mn, x: 0.01, 0.02,…, 0.1) films, grown by electrochemical deposition (ECD) on indium tin oxide (ITO) substrate, was characterized by structural, optical, electrical and magnetic techniques. Energy-Dispersive-X-Ray-Fluorescence (EDXRF) spectroscopy showed 5% dopants A. X-ray diffraction (XRD) measurements clearly showed formation of all Zn0,95A0,05O thin films with a strong c-axis (002) preferential orientation. It was calculated a hexagonal wurtzite structure with XRD results. Absorption measurements of the samples were taken about and an important variation in these measurements were not detected as depend on percentage changes of dopant A. Photoluminescence (PL) measurements showed that PL intensities increase in n-type materials, decrease in p-type materials depending upon increasing doping rate of the grown films. Atomic force microscopy (AFM) pictures of films shows that the most homogeny film is Zn0,95Co0,05O and the most roughness film Zn0,95Mn0,05O. Hall measurements showed that samples doped 5% Fe and Co within ZnO are n-type and other samples doped 5% Ni and Mn within ZnO are p-type. Magnetoresistance (MR) measurements show that all films have feature diluted magnetic semiconductor (DMS) at room temperature. [ABSTRACT FROM AUTHOR]

Monodisperse 8 nm Fe 3 O 4 nanoparticles (NPs) were synthesized by the thermal decomposition of iron(III) acetylacetonate in oleylamine and then were deposited onto n-type silicon wafer having the Al ohmic contact. Next, the morphology of the Fe 3 O 4 NPs were characterized by using TEM and XRD. The optical properties of Fe 3 O 4 NPs film was studied by UV–Vis spectroscopoy and its band gap was calculated to be 2.16 eV. Au circle contacts with 7.85 × 10 −3 cm 2 area were provided on the Fe 3 O 4 film via evaporation at 10 −5 Torr and the Au/Fe 3 O 4 NPs/ n -Si/Al heterojunction device were fabricated. The temperature-dependent junction parameters of Au/Fe 3 O 4 / n -Si/Al device including ideality factor, barrier height and series resistance were calculated by using the I-V characteristics in a wide temperature range of 40–300 K. The results revealed that the ideality factor and series resistance increased by the decreasing temperature while the barrier height decreases. The Richardson constant of Au/Fe 3 O 4 / n -Si/Al device was calculated to be 2.17 A/K 2 cm 2 from the I-V characteristics. The temperature dependence of Au/Fe 3 O 4 / n -Si/Al heterojunction device showed a double Gaussian distribution, which is caused by the inhomogeneities characteristics of Fe 3 O 4 / n -Si heterojunction. [ABSTRACT FROM AUTHOR]

The present study reports on an easy preparation of poly(pyronin Y)/graphene (poly(PyY)/graphene) nanocomposites thin films on indium tin oxide coated glass substrates (ITO). The thin films of poly(PyY)/graphene nanocomposites are prepared by a novel method consisting of three steps; (i) preparation of graphene oxide (GO) thin films on ITO by spin-coating method, (ii) self-assembly of PyY molecules from aqueous solution onto the GO thin film, (iii) surface-confined electropolymerization (SCEP) of the adsorbed PyY molecules on the GO thin film. The as-prepared poly(PyY)/graphene nanocomposites thin films are characterized by using electroanalytical and spectroscopic techniques. Afterwards, the graphene-based polymeric dye thin film on ITO is used as an electrode in an electrochemical cell. Its performance is tested for electrochemical detection of nitrite. Under optimized conditions, the electrocatalytical effect of the nanocomposites thin film through electrochemical oxidation of nitrite is better than that of GO coated ITO. [ABSTRACT FROM AUTHOR]