Yazar "Ocak, Sema Bilge" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    Current voltage analyses of Graphene-based structure onto Al2O3/p-Si using various methods
    (Pergamon-Elsevier Science Ltd, 2020) Efil, Esra; Kaymak, Nuriye; Seven, Elanur; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge; Tataroglu, Adem
    The present study's main purpose is to determine the current-voltage (I-V) performance of Graphene (Gr) based hetero nanostructure produced on Al2O3/p-Si. Graphene synthesis was carried out using the chemical vapor deposition (CVD) technique on Copper (Cu) foils used as a metal catalyst and transferred onto Al2O3/p-Si using the conventional transfer method. The I-V characteristics of this structure were measured in the dark environment, and the electrical properties of the Gr/Si structure were characterized at room temperature. The rectifying ratio (RR) of the structure was found to be about 103 at +/- 3 V. The electrical properties of ideality factor (n), series resistance (R-S), and barrier height (Phi(b)) were examined by using the theory of Thermionic Emission (TE), Norde's method, and Cheung's method. The values of Phi(b), which were calculated using Norde's method, Cheung's method, and the theory of thermionic emission (TE), were found to be 0.69 eV, 0.71 eV, and 0.68 eV, respectively. The ideality factor was found to be approximately 3.89 according to the theory of TE. The values of series resistance were also determined using the Norde's method and Cheung's two different parameters (dV/dln (I) and H(I)) found to be 9.60 k Omega, 9.12 k Omega, and 5.94 k Omega, respectively.
  • Küçük Resim Yok
    Öğe
    Dielectric characteristics and electrical conductivity behavior of graphene/Al2O3/p-type silicon structure
    (Elsevier Science Sa, 2021) Kaymak, Nuriye; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge
    Graphene nanosheets (Gns) obtained by the chemical vapor deposition (CVD) method have been employed for the fabrication of Graphene/Al2O3/p-type silicon (Si) structure. The Raman, scanning-electron-microscopy (SEM) and transmission-electron-microscopy (TEM) have been used to analyze the morphology and structural features of the graphene nanosheet. The dielectric features and electrical-conductivity of Graphene/Al2O3/p-type Si have been studied in the frequency range 10 kHz-400 kHz and in the voltage range,-4 V to +4 V at 300 K. The obtained experimental outcomes imply that electrical conductivity and dielectric features of Graphene/ Al2O3/p-type Si were found out to be powerful functions of frequency and applied bias voltage. It can be seen that almost all of the interface states between metal and silicon contribute to modify of dielectric features of Graphene/Al2O3/p-type Si structure.
  • Küçük Resim Yok
    Öğe
    Electrical properties of Graphene/Silicon structure with Al2O3 interlayer
    (Springer, 2020) Kaymak, Nuriye; Bayram, Ozkan; Tataroglu, Adem; Ocak, Sema Bilge; Orhan, Elif Oz
    The electrical properties of the fabricated Al/Gr/Al2O3/p-Si structure have been analyzed using frequency-dependent capacitance/conductance-voltage (C/G-V) measurements. Graphene (Gr) nanosheets were grown on to copper (Cu) catalyst substrate, which has 99.99% purity, by Chemical Vapor Deposition (CVD) technique, and then the Graphene was transferred on -Al2O3/p-Si by the standard transfer process. The Graphene structures have been characterized by Raman Spectroscopy and Transmission Electron Microscopy (TEM) analyses, and the results of both analyses confirmed the monolayer/bilayer Graphene nanostructure. The forward and reverse bias G- V and C-V measurements of this structure have been performed in 10 kHz-400 kHz and at 300 K. The frequency dispersion in C and G can be evaluated for interface state density ( D it) and series resistance ( R s) values. The values of D it and R s are dependent on frequency and increase with decreasing frequency. The R s - V graph shows a peak form at all frequencies in the depletion region and vanishes with increasing frequency. The obtained results suggest that the prepared structure can be used in electronic device applications.
  • Küçük Resim Yok
    Öğe
    Gamma-ray irradiation effects on capacitance and conductance of graphene-based Schottky diode
    (Elsevier, 2021) Kutluoglu, Esra Efil; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge
    The purpose of this study is to determine the effects of gamma (gamma)-ray irradiation on capacitance and conductance features of Al/Graphene/Al2O3/p-Si structure. Graphene has been grown on copper foil by the Chemical Vapor Deposition (CVD) method and transferred onto Al2O3/p-Si by the wet transfer method. After Al/Graphene/Al2O3/p-Si structure has been exposed to 30 kGy and 60 kGy gamma-ray irradiation, capacitance, and conductance measurements have been accomplished at 300 K. Electrical parameters have been compared before and after gamma-ray irradiation for 50 kHz and 500 kHz. These results have been confirmed that capacitance and conductance values have increased after gamma-ray irradiation and, have decreased when the radiation dose was increased from 30 kGy to 60 kGy. It has been observed that series resistance has decreased after 30 kGy radiation dose and has increased with increasing radiation dose.