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In this work, TiO 2 nanoparticles and nanorods have been synthesized and their structural properties have been investigated in different preparation conditions. The effect of cobalt doping (in different molar ratios of 6, 12, 18 and 24) on physical properties of nanoparticles was studied. Un-doped and cobalt doped titanium dioxide nanoparticles was prepared through the sol-gel method. Nanostructures were characterized by using X-ray diffraction and scanning electron microscopy techniques. The effect of cobalt doping on the magnetic properties is also investigated by vibrating sample magnetometer. It confirmed that cobalt doped TiO 2 nanoparticles show paramagnetic behavior and their magnetic susceptibilities enhanced by increasing the doping level. Results show that increasing of cobalt doping produce a CoTiO 3 phase and the particle sizes increase.

The fabrication of a p-n diode is investigated using a fully solution-processed method. Indium gallium zinc oxide (IGZO) ink was synthesized and deposited on a quartz substrate and annealed to form a thin film serving as an n-type semiconductor. A facile sol-gel method was used to deposit a lithium doped nickel oxide thin film (Li:NiO) as a p-type semiconductor. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the structural properties of Li:NiO and IGZO films. XRD analysis revealed a polycrystalline bunsenite structure in the Li:NiO films. Nanocrystalline grains were also observed on the surface morphology of the Li:NiO films. The XRD analysis indicated that the IGZO films were amorphous. However, SEM images demonstrate a variety of nanostructures in these films, including hexagons. The Li:NiO molar ratio was optimized to minimize series resistance of the diode. NiO had a carrier density of 7.8E13 3 cm  and mobility of 0.8 2 . cm V S  , the highest mobility ever reported in a NiO film to our knowledge. The carrier density of IGZO was 2.5E16 3 cm  ,and its mobility was 0.95 2 . cm V S  . The fabricated diode exhibited a current ratio of 175 in on and off states and a reverse breakdown voltage of 3.5 V