Yazar "Gulcan, Mehmet" seçeneğine göre listele

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    Öğe
    Effects of the r-GO doping on the structural, optical and electrical properties of CdO nanostructured films by ultrasonic spray pyrolysis
    (Springer, 2020) Imer, Arife Gencer; Gulcan, Mehmet; Celebi, Metin; Tombak, Ahmet; Ocak, Yusuf Selim
    Undoped and reduced graphene oxide (r-GO)-doped CdO films were prepared via the ultrasonic spray pyrolysis method with weight ratios of 1, 3 and 5% onto substrates. The successfully prepared films were characterized to understand the influence of r-GO dopant content on the morphological, structural, electrical and optical properties of the films by several diagnostic techniques. XRD measurement confirms that all the films were polycrystalline in the cubic phase of CdO with the preferred orientation (111). The optical band gap of the films decreases with the increase in doping amount. The r-GO@CdO nanostructured films were used as an interfacial layer to fabricate the heterojunction device and to investigate their electrical properties using current-voltage and capacitance-voltage measurements in the dark. The rectification properties of the studied devices increase with the r-GO dopant amount. The obtained results indicate that the r-GO content in the CdO films is responsible for the modification of physical properties of electronic device.
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    Öğe
    The novel pyridine based symmetrical Schiff base ligand and its transition metal complexes: synthesis, spectral definitions and application in dye sensitized solar cells (DSSCs)
    (Springer, 2018) Imer, Arife Gencer; Syan, Ranjdar Hamad Basha; Gulcan, Mehmet; Ocak, Yusuf Selim; Tombak, Ahmet
    The pyridine based azo-linked symmetrical Schiff base ligand, (E)-2,2'-((1E,1'E)-(pyridine-2,6-diylbis(azanylylidene))bis(methanylylidene))bis(4-((E)-phenyldiazenyl)phenol) (H2L), and its Co(II), Ni(II) and Pd(II) transition metal complexes were prepared, and defined by using elemental analysis, Fourier transform infrared, UV-visible, mass, nuclear magnetic resonance spectra, molar conductance, magnetic susceptibility and thermal analysis techniques. The conductivity results pointed out the non-electrolytic nature of all metal complexes. Elemental composition, ultraviolet spectra and magnetic susceptibility data showed that the synthesized complexes are in the binuclear structure and square plane geometry. When compared to the characteristic infrared bands for the functional groups of the ligand structure with complex molecules are reached, the ligand binds to the metal atom via phenolic OH and azomethine-nitrogen. Furthermore, the dye-sensitized solar cells (DSSCs) based on H2L and its metal complexes were fabricated, and photovoltaic properties of these devices were also investigated. The power conversion efficiency of fabricated devices based on ligand H2L can be improved with the incorporation of the transition metal complex.
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    Öğe
    Synthesis, Characterization, DFT Studies, and Photodiode Application of Azo-azomethine-Based Ligand and Its Transition-Metal Complexes
    (Springer, 2018) Tombak, Ahmet; Imer, Arife Gencer; Syan, Ranjdar Hamad Basha; Gulcan, Mehmet; Gumus, Selcuk; Ocak, Yusuf Selim
    An azo-azomethine-based ligand (H2L) and its transition-metal complexes were prepared, and the electronic structure of the synthesized compounds obtained computationally using density functional theory at B3LYP/6-31G (d,p) level. Furthermore, organic-inorganic heterojunctions were fabricated by forming thin films of complexes of H2L and Co(II), Ni(II), and Pd(II) metal on n-Si substrate. The fundamental electrical parameters of the rectifying heterojunctions were identified based on current-voltage data obtained in the dark at room temperature. The photosensing properties of the devices were investigated under illumination at various intensities from 40 mW/cm(2) to 100 mW/cm(2). The results showed that the photoelectrical characteristics of the devices could be modified by the thin film of metal complex, with the best photosensing properties being obtained for the heterojunction based on compound 1.