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Öğe Fluorine-doped tin oxide films via ultrasonic spray pyrolysis: Investigation of physical properties post-annealing and their potential for TCO applications(Elsevier, 2024) Güneş, İbrahim; Sarıca, Emrah; Bilgin, Vildan; Küçükarslan, Ayşe; Özder, SerhatIn this study, undoped tin oxide (SnO2) and fluorine (F)-doped SnO2 (FTO) films at various doping levels were deposited on glass substrates using the ultrasonic spray pyrolysis technique, followed by an annealing process applied to the films after deposition. In line with this, the study reveals the significant impact of the fluorine doping level optimization on certain physical properties such as the structural, optical, and electrical characteristics of the obtained films, and presents the consequences of the variation in these physical properties for adaptability in various optoelectronic applications. No diffraction peaks were observed in the X-ray diffraction patterns of the deposited films. After the annealing process, however, films with a polycrystalline form and a rutile tetragonal crystal structure were obtained. It was observed that the crystallization levels were better in films doped with 5 % and 10 % F. The optical band gap values of the films were determined to vary between 3.35 eV and 3.68 eV. Furthermore, it was found that with the increase in F doping level, the resistivity (ranging from 2.1 Omega cm to 43.5 Omega cm) and sheet resistance (ranging from 1.62x10(5) Omega/sq to 35.9x10(5) Omega/sq) values of the films decreased, while the figure of merit values (ranging from 0.12x10(-8) Omega(-1) to 67.1x10(-8) Omega(-1)) increased. Among all FTO films, it was revealed that films doped with 10 % F exhibited the highest optical transmittance, the lowest electrical resistivity, and the highest figure of merit values.Öğe Improvement of structural, optical and magnetic properties of cobalt oxide thin films by doping with iron(Springer Science and Business Media Deutschland GmbH, 2021) Küçükarslan, Ayşe; Kuş, Esra; Sarıca, Emrah; Akyüz, İdris; Bilgin, Vildan; Demirselçuk, BarbarosIn this study, using the ultrasonic spray pyrolysis technique, undoped and Fe-doped (at 2, 4, 6%) Co3O4 films were deposited on microscope glass substrates at 300 ± 5 °C, and the effect of Fe doping on some physical properties of Co3O4 films was examined. The structural, optical, magnetic and morphological properties of all films were analyzed using X-ray diffractometer, UV–Vis spectrophotometer, vibrating sample magnetometer and atomic force microscope, respectively. Band gap values of Co3O4:Fe films were found to be between 1.98 and 2.12 eV with an additional sub-band corresponding to energies varying between 1.48 and 1.50 eV for all samples. Structural analysis showed that crystallization levels of the films were improved with the Fe doping. Also, hysteresis curves of the films showed weak ferromagnetic characteristics and the magnetic behavior of the films was found to be sensitive to doping amount of Fe. It was found that Fe doping has beneficial effect on some physical properties of Co3O4 films.Öğe Krd'de baryonların sözdeskaler ve tensör form faktörlerinin incelenmesi(2016) Küçükarslan, Ayşe; Ünal, Yasemin; Bağırır, Zeynep; Özpineci, Altuğ; Sarıca, Emrah[Abstract Not Available]Öğe Optimization of chemically sprayed ZnS films by Mn doping(Elsevier, 2021) Demirselçuk, Barbaros; Kuş, Esra; Küçükarslan, Ayşe; Sarıca, Emrah; Akyüz, İdris; Bilgin, VildanIn this study, undoped and Mn doped ZnS films were grown on microscope glass substrates at substrate tem- perature of 400 ± 5 ◦C by using a low cost Ultrasonic Spray Pyrolysis technique, and the effect of Mn doping on some physical properties of ZnS films was investigated. Structural, optical, electrical and morphological prop- erties of all films were analyzed using X-ray diffractometer (XRD), UV–Vis spectrophotometer, two-probe technique and atomic force microscope (AFM), respectively. X-ray diffraction studies showed that all films were formed in ZnS hexagonal structure and the crystallization levels of the films were relatively improved due to the increase in the Mn doping ratio, especially for 4% doped films. It was determined that the average transmittance value of undoped ZnS film in the visible region is 38% and this value increases to 60% for the sample doped by Mn at the highest rate (12%). The band gap values of the films were calculated using the Tauc equation and determined to be between 3.82 and 3.94 eV. Electrical resistivity values of the films decreased significantly due to the Mn doping. Mn doping also caused ZnS films to have uniform surface morphologies consisting of noticeable particle formations. Figure of merit calculations showed that Mn doping has a favorable effect on ZnS films and ZnS:Mn (12%) films may be promising materials for applications such as photovoltaic solar cells and optoelectronic devices.Öğe Tailoring the physical properties of ultrasonically spray pyrolyzed SnS thin films with silver doping(Springer, 2025) Güneş, İbrahim; Sarıca, Emrah; Bilgin, Vildan; Küçükarslan, AyşeIn this study, the effects of silver (Ag) doping on the structural, morphological, optical, and electrical properties of tin monosulfide (SnS) thin films were investigated. The films, undoped and doped with 3%, 6%, and 9% Ag, were deposited using the ultrasonic spray pyrolysis (USP) technique at a substrate temperature of 350 degrees C. X-ray diffraction (XRD) analysis confirmed a pi-SnS (cubic) structure with (400) preferred orientation for undoped and <= 6% Ag-doped films, while 9% doping induced amorphization due to severe lattice distortions. Morphological analyses revealed smooth, void-free surfaces, with average roughness increasing from 5.8 nm (undoped) to 19.6 nm (9% doping). Optical measurements showed that the band gap widened from 1.84 eV (undoped) to 2.47 eV (9% Ag-doped), and Urbach energy increased from 190 meV to 600 meV. Hall effect measurements confirmed p-type conductivity for all films. Resistivity ranged from 4.34 x 10(5) Omega cm to 9.48 x 10(5) Omega cm, carrier concentration varied between 2.7 x 10(12) cm(-3) and 5.6 x 10(12) cm(-3), while mobility decreased from 3.3 x 10(1) cm(2)/Vs to 2.0 x 10(1) cm(2)/Vs with increasing Ag doping. These findings demonstrate that Ag doping significantly influences the structural and optoelectronic behavior of SnS thin films, making them promising candidates for thin-film solar cells and optoelectronic applications.Öğe The Effect of Fe and Co doping on the Physical Properties of CdO Films Deposited by Ultrasonic Spray Pyrolysis(Springer, 2025) Demirselçuk, Barbaros; Güneş, İbrahim; Sarıca, Emrah; Kuş, Esra; Küçükarslan, Ayşe; Bilgin, VildanIn this study, Cadmium Oxide (CdO) semiconductor films with different iron (Fe) and cobalt (Co) concentrations have been produced at 350 degrees C substrate temperature on the glass substrates by the ultrasonic spray pyrolysis method. In the first part of this study, the Fe element was doped in different ratios (2, 4, 6%) to CdO films, and the films were characterized. At the end of this stage, the optimum Fe doping ratio was determined for CdO films. In the second step, CdO films were dually doped with Fe + Co. The electrical resistivities of CdO:Fe films were determined using a four-probe technique to measure their conductivities, carrier concentrations, mobilities, and electrical conductivity types through Hall measurements. The produced films showed n-type electrical conductivity. It was determined that with increasing doping ratios, the electrical resistivity generally increased, and the films exhibited n-type conductivity. The XRD patterns revealed that the crystal structures of the films were polycrystalline and cubic in structure. The lections of (111), (200), (220), (311), and (222) planes were observed in the XRD patterns. Upon examination of the SEM images, it was observed that the films had nearly homogeneous surfaces and good adhesion to the substrate. By utilizing the fundamental absorption spectra of the films, it was determined that they exhibited direct bandgap transitions, and the bandgap energy values ranged from 2.34 to 2.65 eV. In the structural analysis, all films were found to have a polycrystalline structure and cubic CdO crystal system. When the SEM images of CdO:(Fe + Co) films were examined, it was observed that the films had almost homogeneous surfaces. Based on all these analyses, it was concluded that the doping elements Fe and Co significantly influenced the physical properties of CdO thin films.
