Theses supervised by Dr. Öğr. Üyesi İlker Kara
10 theses · Çankırı Karatekin Üniversitesi
Investigation of structural, morphological, andoptical properties of Cu-Sn doped ZnO films by silar method
Due to its high permeability and abundance in nature, ZnO semiconductor is widely used in technological applications. ZnO nanocrystal is an alternative to other oxide materials because its structural, optical and electrical properties can be improved by adding appropriate doping. Doped and undoped ZnO thin films can be grown by different methods. In this study, FTO/ZnO, FTO/ZnO/Sn-Cu 1%, FTO/ZnO/Sn-Cu 2%, FTO/ZnO/Sn-Cu 3% doped films were obtained by using the SILAR method. The structural properties of the produced ZnO thin films were investigated depending on the additive concentration. The structural and morphological properties of the produced thin films were examined by X-Ray Diffraction Device (XRD), Scanning Electron Microscope (SEM) and UV-VIS spectrometry (UV-VIS). From the XRD anaysis, it was determined that the structure of the produced thin films changed from amorphous structure to polycrystalline structure as the Cu and Sn concentration ratio changed. From the SEM images, it was observed that the morphological properties of the produced thin films changed depending on the additive concentration. The band gaps of the produced thin films were determined by UV-VIS spectrometry. It was observed that the obtained results were compatible with the literature, and a change in the forbidden energy gaps as the doping ratio increased was observed
Production and investigation of antibacterial properties of doped Sn-Cu ZnO thin films
Today, ZnO (zinc oxide) based semiconductor samples, which have great potential, are the most frequently preferred materials to develop devices based on nanotechnology. It is also used in studies due to its excellent chemical stability, biological non-toxicity, and low cost. In this study, undoped thin films and Sn-Cu doped ZnO thin films at different concentrations were grown on FTO substrates by using the SILAR method. Undoped ZnO thin films and Sn-Cu doped thin films were accumulated on the FTO substrate in different concentrations 40 times, and then they were annealed at 300 °C. Properties, which are structural, surface morphological, antibacterial properties, bacterial adhesion, and survival organism count, of undoped thin films and Sn-Cu doped thin films were investigated by using SEM-EDS, the agar diffusion test, and the organism counting method. From the SEM-EDS analysis, it was observed that both undoped and doped films with different Sn-Cu concentrations enlarged harmoniously on the FTO substrate. Their morphological properties changed depending on the doping concentration. It was observed that the produced samples did not show antibacterial activity. The highest adhesion rate of bacterial organisms on the produced samples was observed when the ZnO/Sn-Cu doping rate was 3 %. In addition, the lowest adhesion rate was observed when the ZnO/Sn-Cu additive ratio was 1 %.
Growing doped (Cu-Sn) and undoped zno semiconductor thin films by SILAR method; structural and electrical characterization
In this thesis study, structural and electrical characterization of undoped and Sn-Cu doped ZnO thin films grown on ITO substrate by using the SILAR method were performed. The grown thin films were obtained by performing 40 times SILAR cycle and annealed at 300 °C. Doped ZnO thin films were obtained by keeping the copper (Cu) doping ratio constant and changing the tin (Sn) doping ratio from 1 % to 3 %. The structural, surface morphological and electrical properties of the produced undoped and Sn-Cu doped thin films were investigated. From SEM analyzes, it was observed that the films produced without additives and with different concentrations of Sn-Cu grew spherically (from 64 nm to 177 nm) depending on the concentration on the ITO substrate, and their morphological properties changed depending on the doping concentration. From electrical analyzes, doping processes at different rates (I-V) give positive results and it is thought that produced thin films can be used as a transparent carrier film (TCO) because they do not have high resistance.
Investigation of antibacterial properties of doped ZnO thin films prepared by silar technique
Metal oxides show semiconductor properties with their structures consisting of two or more elements. It is especially preferred due to its electrical conductivity, optical properties, chemical stability, biological non-toxicity and low cost. ZnO is one of the most preferred metal oxides in technological applications today. In this thesis study, undoped ZnO thin films and ZnO thin films with different additives were grown on ITO substrate by using the SILAR method. Thin films have been grown by the SILAR method in 40 cycles and then samples have been annealed at 300 ℃. Structural, surface morphological, antibacterial and bacterial adhesion and survival properties of undoped, Ni-doped and Al-doped ZnO/ITO thin films were investigated. SEM/EDS method was used for surface morphology, agar diffusion test was used for bacterial analysis, and also organism count method was used for bacterial adhesion and survival. Surface morphologies of undoped, Ni-doped and Al-doped thin films showed differences in SEM analysis. Moreover, it has been determined that spherical, clustered and layer-shaped structures are formed. The antibacterial activities of the agar diffusion test were examined and it was seen that it did not show antibacterial activity to the produced samples. In bacterial adhesion and survival organism count, the highest adhesion rate was observed in the Ni-doped thin film.
Production and characterization of ZnO and Al doped ZnO films by SILAR method
In this study, undoped ZnO and Al-doped ZnO thin films at different concentrations were successfully grown on ITO substrate by SILAR (Sequential Ionic Layer Adsorption and Reaction) method. The thin films produced were characterized by scanning electron microscopy (SEM/EDS), X-ray diffraction (XRD), and UV-VIS spectroscopy. According to the XRD analysis results, it was observed that the produced thin films crystallized at the nanoscale and that the crystallization quality changed depending on the Al additive concentration. SEM/EDS analysis results showed that the concentration of Al doping has a significant effect on the morphology of ZnO thin films. UV-VIS analysis results showed that there were significant differences in both optical band gap values and transmittance of the produced thin films depending on the additive.
Antibacterial activities of nickel doped zno thin films prepared by silar method
ZnO thin films are widely utilized in various technological applications due to their low cost, wide bandgap, high electrical conductivity, and optical transparency. This thesis investigates the structural and surface morphology, antibacterial properties, bacterial adhesion, and organism survival count of nickel (Ni) doped ZnO thin films grown on FTO substrates produced by the SILAR method. The nickel (Ni) doping ratio in the ZnO thin films was varied from 1 % to 3 %. SEM-EDS analysis showed that nano-flower structures were formed on the surface of the ZnO thin films. It was observed that the structures formed were dependent on the nickel doping. Among the produced samples, FTO-Ni 2 % exhibited the highest antibacterial activity against E. coli ATCC 35218, while no activity was observed against S. aureus ATCC 25923. In addition, the highest bacterial adhesion rate was observed on the sample doped with Ni 2 %.
Investigation of biosensor properties of Cu-Sn doped ZnO:ITO nanoparticles
In recent studies, ZnO semiconductor is one of the most preferred materials due to its high conductivity, high transmittance and wide band gap. In this thesis study, the structural, surface morphology, antibacterial properties, bacterial adhesion and number of survival organism properties of Cu-Sn doped ZnO thin films grown on ITO substrate produced by the SILAR method were investigated. From SEM analyzes, it was observed that the films produced with different concentrations of Sn grew spherically depending on the concentration on the ITO substrate, and the surface morphology turned into a tighter structure with an increase in the amount of Sn additives. The highest adhesion rate of bacterial organisms on the produced samples was observed when the ZnO/Cu-Sn doping rate was 3 %. In addition, the lowest adhesion rate was observed when the ZnO undoped.
Structural, morphological and optical characterization of Cu-doped CdO nanoparticles produced by spray prolization method
The unwanted hazards of X-rays, gamma rays, and neutrons that can cause significant harm to nearby individuals can be prevented by using several protective materials capable of reducing or absorbing such radiation. Materials like lead and other high atomic number (Z) materials are used to reduce this high-energy radiation. However, high Z elements do not have the ability to block all types of radiation, especially neutron emissions in space or nuclear laboratories. Therefore, lightweight and processable "lead-free" materials like polymer composites reinforced with fillers are used in device applications in various fields, including medicine, due to their radiation attenuation capabilities and superior properties. In this study, copper oxide nanoparticles/PMMA composite films were produced using the spray pyrolysis method. Cu doped CdO nanoparticles were synthesized via the spray pyrolysis method in an oxidizing atmosphere using pure copper as the target to investigate the effect of laser output on the properties of the synthesized nanoparticles. The morphological and optical characterization of the prepared thin films was conducted. Additionally, gamma radiation shield tests were performed as an application for the prepared films
The growth of doped ZnO thin films by the silar method and investigation of structural, optical and electrical properties
In recent years, the production and characterization of nano-sized structures and thin films of semiconductor materials have become significant subjects of research and application across various fields of science and technology. One of these areas of interest is the synthesis and characterization of zinc oxide (ZnO) thin films. ZnO has garnered substantial attention due to being a semiconductor material with a wide energy bandgap and possessing unique electrical, optical, and structural properties. Additionally, these films offer potential for a range of applications, especially in areas such as semiconductor devices, optoelectronic devices, solar cells, and sensors. In this thesis study, structural and electrical characterization was conducted on undoped ZnO and Sn- and Cu-doped ZnO thin films grown on ITO substrates using the SILAR method. Thin film samples were obtained by performing 40 SILAR cycles and subsequently annealed at 300 °C. The structural, surface morphological, and electrical properties of the produced undoped ZnO and Sn- and Cu-doped ZnO thin films were examined. SEM analysis revealed that the surface morphology of the undoped ZnO thin film sample exhibited the formation of spherical structures with some voids on the substrate. The Sn-doped ZnO thin film sample exhibited growth in the form of nano-flower structures on the ITO substrate. The formed structures formed fractured layers in certain areas while voids were present in other regions. The surface morphology of the Cu-doped ZnO thin film sample indicated the formation of a flat and relatively thicker layer on the ITO substrate, exhibiting fractures that created voids. Electrical analysis (I-V) showed positive results of doping with different elements. This suggests that the produced thin films could be used as transparent conducting films (TCO) due to their low resistance.
Investigation of the effect of nickel doped on the structural surface and optical properties of zno thin films prepared by the silar method
Thin film technologies play a significant role in the development of modern electronic and optoelectronic devices. These technologies attract considerable interest in many application areas by enabling the production of high-performance and low-cost materials. Zinc oxide (ZnO) thin films stand out as a potential material for various electronic and optical devices. Thin film technologies in this field promise high efficiency and low-cost devices. ZnO is a semiconductor material with a wide energy range, making it an attractive option for use in electronic and optoelectronic devices due to its optical properties and high electron transport capabilities. Additionally, the physical and chemical properties of ZnO indicate a wide range of potential applications, from surface coatings to sensors in various industrial applications. Especially, doped ZnO semiconductor materials grown on FTO (fluorine-tin-oxide) substrates are significant candidates for many applications such as solar cells, gas sensors, and biosensors. In this thesis study, undoped FTO/ZnO and Nickel (Ni) doped, Ni 1% FTO/ZnO, Ni 2% FTO/ZnO, and Ni 3% FTO/ZnO thin films prepared using the SILAR (Successive Ionic Layer Adsorption and Reaction) method were investigated. The influence of nickel's contribution on the structural, surface, and optical properties of the produced films was particularly studied. Structural analyses were conducted using techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The findings indicate significant changes in the crystal structures and surface morphologies of nickel-doped FTO/ZnO thin films. Additionally, the optical properties were examined using UV-Vis spectroscopy, and the impact of nickel on the film's optical characteristics was thoroughly ii evaluated. Nickel doping levels in the ZnO thin films were altered from 1% to 3%. SEM EDS analyses revealed that the produced ZnO thin films formed cluster-like structures. It was observed that the structures varied depending on the nickel content. Surface homogeneity distribution was most evident in the FTO/ZnO-Ni 3% sample among the produced specimens. XRD analyses identified the dominant diffraction peaks of the samples as SnO2 (FTO-substrate). Overall, the samples exhibited a tetragonal crystal structure with orientations of (101), (202), and (211). As the Ni-doped concentration increased, an increase in peak intensities and a decrease in half-peak widths in the films were observed. These results demonstrate the potential use of the produced samples in solar cell technologies, semiconductor-based gas sensor fabrication, and similar fields.