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Öğe A comparative study on cobalt and aluminum as a dual doping element for CdO films(Elsevier Sci Ltd, 2019) Cavusoglu, H.; Aydin, R.; Sahin, B.In the present study, we have delineated the synthesis of transparent conductive un-doped, Co doped (Co0.01Cd0.99 O) and Co:Al dual-doped CdO films [(Al-m,Co0.01Cd0.99-m) (m: 0.005, 0.01 and 0.02, respectively)] by using facile successive ionic layer adsorption and reaction (SILAR) method at room temperature. Scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopic measurements had been executed to reveal the influence of Co and Al dopants on the morphological, crystallinity and optical characteristics of CdO films. The effect of Co doping and Co:Al dual doping on the surface morphology of CdO films was identified through SEM analysis. The EDX analysis results confirmed the presence of Co2+ and Al3+ dopant ions in the CdO lattices. The XRD measurements revealed that all of the SILAR-grown CdO films were polycrystalline with a cubic structure and exhibited (111) and (200) preferred orientations. The presence of chemical bonding was verified by FT-IR spectroscopic investigation. Furthermore, the optical band gap (E-g) values of the all deposited films were evaluated from UV-Vis spectrophotometric data. The ES values of all the films were remarkably widened in proportion to the Al doping from 1.92 eV to 3.05 eV. The investigations have shown that mono doping and dual doping have a substantial impact on the physical properties of SILAR-grown CdO films.Öğe The effect of thymus syriacus plant extract on the main physical and antibacterial activities of ZnO nanoparticles synthesized by SILAR method(Elsevier, 2022) Sahin, B.; Aydin, R.; Soylu, Soner; Turkmen, M.; Kara, M.; Akkaya, A.; Cetin, H.This study aimed to determine the main physical properties of green synthesized ZnO nanoparticles (ZnO-NPs) using Thymus syriacus plant extract and their antibacterial activities against eight different Gram-positive and Gram-negative plant bacterial disease agents. The surface morphological, structural, optical and electrical attributes of the ZnO films were analyzed by various types of characterization techniques. The authors have observed that the microstructural and surface morphological properties considerably changed by using T. syriacus plant extract. UV-Vis. analysis showed that the bandgap values are increased from 3.17 to 3.28 eV with the T. syriacus content in the growth solution. Impedance measurements presented an increase of the semicircle diameters with the increase % of T. syriacus. The antibacterial effectiveness of ZnO-NPs was evaluated against plant pathogenic bacterial species by using the agar disc diffusion method. Established on inhibition zone diameter values, ZnO-NPs displayed varying levels of antibacterial activities against all bacterial species tested. Gram-positive bacterial species were found more sensitive than Gram-negative species. In comparison, the highest antibacterial activity was displayed against Clavibacter michiganensis subsp. michiganensis and Bacillus subtilis subsp. subtilis, the lowest antibacterial activity was recorded for Pseudomonas corrugata. The present research findings suggest that the green synthesized ZnO-NPs have a prospective to be used as optoelectronic materials and antibacterial agents against plant pathogenic bacterial disease.Öğe A green approach for the preparation of nanostructured zinc oxide: Characterization and promising antibacterial behaviour(Elsevier Sci Ltd, 2021) Tasdemir, A.; Aydin, R.; Akkaya, A.; Akman, N.; Altinay, Y.; Cetin, H.; Sahin, B.In the present study, nanostructured zinc oxide (ZnO) films have been successfully synthesized using fruit extract of Viburnum opulus L. (VO) on glass slides by successive ionic layer adsorption and reaction (SILAR) procedure. The impact of VO concentrations on the structural, morphological, optical, electrical, and antibacterial attributes of ZnO films has been investigated in detail. The samples' XRD patterns present a hexagonal crystal structure with a preferential orientation along the (002) plane. The crystallite size values of ZnO samples were found to be in the ranges from 14.88 to 9.23 nm. The supplementation of VO to the synthesis solution remarkably affected the surface morphological features of the ZnO films. The optical results demonstrated that band gap energy values of the ZnO films at room temperature were decreased from 3.20 to 3.07 eV as a function of VO content in the bath solution. The films' electrical properties were determined by impedance analysis in the frequency range of 20 Hz -1 MHz. Impedance-frequency measurements showed VO insertion to ZnO thin films cause an increase in impedance value at the low frequencies. Cole-Cole plots with a single semi-circle confirmed the contribution of grain and grain boundary for the electrical conduction process. The agar disk diffusion method was used to test the antibacterial properties of ZnO/VO inserted ZnO and inhibition zones were measured. VO inserted ZnO showed a stronger inhibitory effect on gram-positive bacteria Staphylococcus aureus (ATCC 25923) and gramnegative bacteria Escherichia coli (ATCC 35218) than ampicillin antibiotic used as a control group. In line with the promising bactericidal results of a new generation, VO inserted ZnO, the nanostructured product with this study, it can also be applied in multidrug-resistant clinical isolates obtained from patients.Öğe Li:Ce co-doped CdO films synthesized by SILAR method: Effects of rare earth element Ce content on the physical attributes(Elsevier Sci Ltd, 2018) Aydin, R.; Sahin, B.Undoped, Li-doped (Li0.02Cd0.98O) and Li:Ce co-doped (Ce-x Li0.02Cd0.98-xO (x = 0.005, 0.01 and 0.02)) CdO nanofilms were prepared by a successive ionic layer adsorption and reaction (SILAR) process. The effects of the Li and Li:Ce doping on the main physical properties such as crystal structure, surface morphological characteristics and optical features like bandgap and transmittance of obtained these films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis spectrophotometer respectively. X-ray diffractogram analysis verified that the synthesized CdO films pertain to the cubic structure. XRD analysis indicated the growth of CdO with polycrystalline form for preferential orientation along the (111) and (200) plane. It is obviously seen from the SEM micrographs that Li doping and Li:Ce co-doping induce remarkable changes in the CdO surface morphology. The UV-Vis spectroscopy analysis results show that the (2.0% Li + 1.0% Ce) Li:Ce co-doped CdO films exhibits maximum transmittance (27%) in the range between 300 and 1100 nm and high optical bandgap energy (E-g = 2.92 eV).Öğe Light-weight and flexible Ni-doped CuO (Ni:CuO) thin films grown using the cost-effective SILAR method for future technological requests(Springer, 2022) Aydin, R.; Akkaya, A.; Sahin, B.Products based on nanostructured flexible thin films, which are anticipated to make their way into our lifetimes in the near future. Therefore, nanostructured metal-oxide thin-film materials grown on flexible substrates are anticipated to meet emerging technological requests. In this article, we present a promising light-weight and flexible thin-film material using un-doped and Ni-doped CuO samples. Ni:CuO flexible thin-film materials were fabricated by using the cost-effective SILAR method on cellulose acetate substrates and the effects of both Ni doping and bending on the change in electrical and optoelectronic performances were investigated. It is observed that Ni doping has a great impact on the main physical properties of flexible CuO samples. The optical bandgap value of the un-doped CuO film improves with increasing Ni ratio in the growth bath. Also, sheet resistance values of the un-doped and Ni:CuO samples are a little affected due to bending of samples for bending radius similar to 20 mm. These flexible all solution-processed nanostructured CuO samples are promising candidates for use in future optoelectronic applications.Öğe Production of p-CuO/n-ZnO:Co nanocomposite heterostructure thin films: An optoelectronic study(Elsevier Sci Ltd, 2023) Kahveci, O.; Akkaya, A.; Yucel, E.; Aydin, R.; Sahin, B.The p-n junction is the principal mode of optoelectronic semiconductor material. At present, we submit a solution-based attempt at the synthesis of nanostructured p-type CuO and n-type ZnO nanocomposite (NC) heterostructure films. Bare and Cobalt (Co)-doped CuO-ZnO NC films have been produced on glass slides using the SILAR (Successive Ionic Layer Adsorption and Reaction) method. The influence of Co-doping concentration on the physical characteristics of CuO-ZnO NC heterostructure films was investigated. XRD spectrums indicated the phase and structural purity of solution-based synthesized CuO-ZnO NC samples. The surface topographical, as well as optical and electrical properties of heterostructure films were, also investigated. While the bare CuO-ZnO NC film has a-38% transmission near 1000 nm wavelength region, the 2.0% Co-doped CuO-ZnO NC film has-31% of optical transmission. The sheet resistance value of the grown 2.0% Co:CuO-ZnO NC sample is almost 13 times lower than that of the bare CuO-ZnO NC sample at 400 K temperature. As a consequence, our attempt ensures a novel strategy for the production and performance optimization of CuO-ZnO NC hetero-structures in the implementation of optoelectronics.Öğe SILAR derived CdO films: Effect of triethanolamine on the surface morphology and optical bandgap energy(Elsevier Science Bv, 2018) Sahin, B.; Aydin, R.Nanostructured CdO films have been successfully synthesized with different ratios of surfactant triethanolamine (TEA) under SILAR condition. The influence of addition of TEA on the physical properties of CdO nanoparticles was studied. The surface morphology of the films was studied by metallurgical microscope and SEM analysis. Surface topography of the film was studied by AFM. The structural properties of the samples were studied by X-ray diffraction (XRD). The XRD studies confirm that the deposited CdO films has cubic structure (111) preferred orientation with well-crystallinity and purity. The optical bandgap energy was estimated based on the UV-vis spectroscopies which were obtained in the range of 2.16 eV-2.46 eV. Our study is encouraging to get enhanced surface topography by surfactant TEA.Öğe Solution-processed nanostructured ZnO/CuO composite films and improvement its physical properties by lustrous transition metal silver doping(Springer, 2020) Akkaya, A.; Sahin, B.; Aydin, R.; cetin, H.; Ayyildiz, E.This paper has reported the fabrication and characterization of pristine, and silver (Ag)-doped nanostructured ZnO/CuO composite thin films that have not been previously reported. The thin films were synthesized by the successive ionic layer adsorption and reaction (SILAR) technique. The morphological, crystalline structure, optical and electrical characterizations of the films have been achieved utilizing scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectrum (FTIR) analysis, ultraviolet-visible (UV-Vis) spectrophotometry and the four-point probe measurements. Particle sizes of pristine and Ag-doped ZnO/CuO thin films were found to vary from 32 to 58 nm. Crystallite size was changed from 16.40 to 18.90 nm with changing Ag dopant in the ZnO/CuO composite film. FTIR spectra that have the absorption peaks at similar to 725 and similar to 510 cm(-1) referred to the stretching vibration of Zn-O and Cu-O bonds during the synthesis of ZnO/CuO nanofilms. The bandgap values of ZnO/CuO composite films increased from 2.05 to 2.36 eV as Ag content increased from 0 to 2 M%. The activation energies of the samples were obtained from the Arrhenius plots of sigma versus 1/T. The multiple activation process was observed. It was noteworthy that Ag-doping results in a significant difference in conductivity at all temperature values.Öğe Superior antibacterial activity against seed-borne plant bacterial disease agents and enhanced physical properties of novel green synthesized nanostructured ZnO using Thymbra spicata plant extract(Elsevier Sci Ltd, 2021) Sahin, B.; Soylu, Soner; Kara, M.; Turkmen, M.; Aydin, R.; Cetin, H.An easy and eco-friendly approach using Thymbra spicata var. spicata L. (TS) plant extract was developed for the formation of nanostructured ZnO. TS aqueous leaf extract was used for the green synthesis of nanostructured ZnO via the Successive ionic layer adsorption and reaction (SILAR) method. Electron microscope images exhibit the morphological adjustments of the samples with respect to change in TS concentration in the growth solution. The nanostructured ZnO grown by SILAR was observed to be polycrystalline with hexagonal crystal structure. The optical energy bandgap value of the samples varies from 3.21 to 3.09 eV as the content of TS increases from 2.5 to 5.0%. Also, the effect of TS additive to ZnO on electrical properties was investigated. It was determined by Van der Pauw measurements that TS contribution to ZnO significantly increased electrical resistance. In addi-tion, impedance analyzes of the produced films were carried out in the frequency range of 20Hz -1 MHz. Nyquist plots showed the single semicircle for all samples, and the values of capacitance and resistance were calculated. Its antibacterial activities was investigated against economically important Gram-positive (Clavibacter michiganensis subsp. Michiganensis) and negative (Pseudomonas syringae pv. Phaseolicola, Pseudomonas cichorii and Pectobacterium carotovorum subsp. Carotovorum) seed-borne plant bacterial disease agents by using paper disc diffusion assay for the first time. In vitro laboratory screenings of green synthesized nanostructured ZnO have given encouraging results, indicating their potential use in the management of seed-borne bacterial diseases.Öğe Synthesis of Al and In dual-doped CuO nanostructures via SILAR method: Structural, optical and electrical properties(Elsevier, 2023) Kahveci, O.; Akkaya, A.; Aydin, R.; Sahin, B.; Ayyildiz, E.In this article, we investigated the doping characteristics of Al-doped CuO (ACO), and Al/In co-doped CuO (AICO) thin films, which were synthesized on glass substrates, via the solution-based successive ionic layer adsorption and reaction (SILAR) technique. The surface morphological, chemical composition, structural, optical, and electrical properties of the nanocrystalline films were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), Ultraviolet-visible (UV-vis.) spectrophotometry, and Transmission Line Method (TLM), respectively. Surface morphology studies exhibited that a decrease in the films' thickness caused an increment in the optical transmittance. XRD patterns displayed that the obtained samples were polycrystalline and crystallized in a bare CuO monoclinic structure. FTIR studies of the CuO samples displayed that Al and In codoping influenced the forms and the violence of the absorption bands. The optical bandgap energy of bare CuO was determined to increase from 1.45 to 1.78 eV as a result of the co-doping. The substitution of In displayed in the irregularity of the morphology, owing to its wide ionic radius, which caused an increase in band gap energy and a decrease in resistance. The co-doping of Al and In is hence anticipated to ensure an extensive range of physical and optical properties of nanostructured metal oxide samples for a variety of technological applications.Öğe Transition metal Mn/Cu co-doped CdO transparent conductive films: Effect on structural, morphological and optical characteristics(Elsevier Science Sa, 2019) Aydin, R.; Cavusoglu, H.; Sahin, B.The transparent conducting un-doped, Cd-0.99 Mna(0.01)O (Mn: 1.0%) and Mn/Cu co-doped CdO [(CuxMn0.01Cd0.99-x) (x: 0.005, 0.01 and 0.02 respectively)] films were prepared by successive ionic layer adsorption and reaction (SILAR) technique on soda lime glass substrates. The effect of Mn and Cu-dopant on structural, morphological and optical characteristics of the CdO films was analyzed by XRD, SEM, UV-Visible spectrophotometer and FT-IR spectroscopy. The XRD studies showed that the all-SILAR prepared films were polycrystalline and had preferential growth along the (111) directions. SEM analysis revealed that the Mn doping and Mn/Cu co-doping significantly influenced the surface morphologies of the CdO films. The EDX results confirmed that the dopant ions were incorporated properly into the CdO lattices. The optical band gap energy values of the all deposited films were determined by extrapolation method and observed to be in the range of 2.08-2.38 eV. Optical analysis results disclosed that doping alters the band gap facilitating the potential of transparent conductive films to be exploited in optoelectronic devices. Furthermore, FT-IR was used to confirm the existence of metal-doped CdO. The investigations showed that co-doping significantly affects the physical properties of SILAR-grown CdO films. (C) 2019 Elsevier B.V. All rights reserved.
