Yazar "Ibrahimoglu, Erhan" seçeneğine göre listele

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    The dielectric characteristics of spray deposited α-Si3N4:ZnO thin films: The nitride effect on frequency-dependent capacitance and conductance profiles
    (Elsevier, 2024) Ibrahimoglu, Erhan; Demir, Ahmet; Caliskan, Fatih; Tatli, Zafer
    The study focused on the effect of alpha-Si3N4 doping on the electrical/dielectric properties of ZnO thin films. Both alpha-Si3N4 doped and additive-free ZnO thin films were coated on p-Si substrates via a spray deposition method to achieve this. The electrical (current density (J)-voltage (V)) and dielectric properties (capacitance (C), conductance (G), dielectric loss (tan delta), reel/imaginary part of dielectric permittivity (epsilon ' and epsilon '') and electric modulus (M ' and M '')) were determined for all samples by using dielectric spectroscopy (DS) method. On the other hand, scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS) analysis were performed to evaluate microstructure, X-ray diffraction (XRD) was used to define chemical composition and atomic-force microscopy (AFM) analysis was carried out to characterise the topology of the coating layers. The thickness/surface roughness was obtained as similar to 82.5 nm/10.6 nm for undoped and- 99.5 nm/10.4 nm for nitride-doped samples, respectively. The maximum capacitance value (C) was obtained as 275 pF at -3.0V and 200 Hz, and the optimal conductance (G) value was also found as 45 mu S around 4.0V and 1 MHz in the nitride-doped sample. The average of alpha and tau values was calculated as 5.67 x 10(-5) s, 0.146 and 4.49 x 10(-5) s, 0.081 for nitride-doped and undoped ZnO, respectively. The increase in performance can be attributed to the homogeneous and almost equally-size distribution of the ZnO grain growth which is strongly controlled by alpha-Si3N4.
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    Investigating ultra-thin rGO coated ZnO core-shell structures in MOS devices: Electrical/dielectric characteristics and relaxation mechanism
    (Elsevier, 2024) Kirkbinar, Mine; Ibrahimoglu, Erhan; Demir, Ahmet; Caliskan, Fatih
    The study focused on the relaxation and polarisation mechanisms of Al/(rGO:ZnO core-shell)/pSi/Al MOS structures. For this purpose, the rGO:ZnO core-shell structures were synthesised by sol-gel procedures and coated on pSi by spin-coating. The structures were characterized as chemical, morphological and micro-structural using FESEM-EDS, AFM, XRD and Raman analysis. Additionally, the capacitance (C), conductance (G/omega), dielectric permittivity (epsilon ' and epsilon ''), loss factor(tan delta), electric modulus(M ' and M '') of the samples were successfully examined by DS over the wide range of frequencies (100 Hz-1 MHz) for determining dielectric parameters. Three distinct regions were visible on the C-V and C-omega plots: accumulation (-4 to 0 V), depletion (0 to 2 V), and inversion (2 to 4 V). Two relaxation times (10(-4)s-10(-7)s) were obtained in epsilon '-V and epsilon '-omega graphs between 1-100 kHz (region 1) and 100 kHz-1 MHz (region 2). The relaxation times were according to the Maxwell-Wagner and dipolar polarisation mechanism. As a result, the capacitive effect was observed and the equivalent RC circuit obtained from the Cole-Cole diagrams allowed the samples to be used in energy storage or different electronic applications.