Yazar "Cetinkaya, H. G." seçeneğine göre listele

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    A comparative study on the electrical parameters of Au/n-Si Schottky diodes with and without interfacial (Ca1.9Pr0.1Co4Ox) layer
    (World Scientific Publ Co Pte Ltd, 2016) Kaya, A.; Cetinkaya, H. G.; Altindal, S.; Uslu, I.
    In order to compare the main electrical parameters such as ideality factor (n), barrier height (BH) (Phi(I-V)), series (R-s) and shunt (R-sh) resistances and energy density distribution profile of surface states (N-ss), the Au/n-Si (MS) Schottky diodes (SDs), with and without interfacial (Ca1.9Pr0.1Co4Ox) layer were obtained from the current Z voltage (I-V) measurements at room temperature. The other few electrical parameters such as Fermi energy level (E-F), BIT (Phi(C-V)), Re and voltage dependence of N-ss profile were also obtained from the capacitance voltage (C-V) measurements. The voltage dependence of N-ss profile has two distinctive peaks in the depletion region for two diodes and they were attributed to a particular distribution of N-ss located at metal semiconductor (MS) interface. All of these results have been investigated at room temperature and results have been compared with each other. Experimental results confirmed that interfacial (Ca1.9Pr0.1Co4Ox) layer enhanced diode performance in terms of rectifier rate (RR = I-F/I-R at +/- 3.4 V), N-ss (at 0.5 eV) and Rsh (-3.4 V) with values of 265, 5.38 x 10(13)eV(-1).cm(-2) and 7.87 x 10(4) Omega for MS type Schottky barrier diode and 2.56 x 10(6), 1.15 x 10(13) eV(-1).cm(-2) and 7.50 x 10(8) Omega for metal insulator semiconductor (MIS) type SBD, respectively. It is clear that the rectifying ratio of MIS type SBD is about 9660 times greater than MS type SBD. The value of barrier height (BIT) obtained from C-V data, is higher than the forward bias I-V data and it was attributed to the nature of measurements. These results confirmed that the interfacial (Ca1.9Pr0.1Co4Ox) layer has considerably improved the performance of SD.
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    Electrical and dielectric properties of Au/1% graphene (GP)+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structures as function of temperature and voltage
    (Canadian Science Publishing, 2015) Cetinkaya, H. G.; Kaya, A.; Altindal, S.; Kocyigit, S.
    Electrical and dielectric properties of Au/1% graphene (GP)+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structures have been investigated using the admittance spectroscopy method in the temperature and voltage ranges of 160-300 K and -4-5 V, respectively. Experimental results show that both the main electrical and dielectric parameters, such as barrier height (Phi(b)), depletion layer width (W-d), series resistance (R-s) of structure, real and imaginary parts of dielectric constant (epsilon', epsilon '') and electric modulus (M' and M ''), tan delta, and AC conductivity (sigma(ac)) were found to be strong functions of temperature and applied bias voltage. M' and M '' versus V plots have a peak at about 1 V. While the peak position shifted towards negative biases, the magnitude of the peak decreases with increasing temperature. Such peak behavior in M' and M '' can be attributed to the existence of particular density distribution profile interface states at the interfacial layer-n-Si interface and their reordering and restructure under external electric field and interface polarization. These peaks also indicated that the Au/1% GP+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structure exhibits relaxation phenomena.
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    On the temperature dependent forward bias current-voltage (I-V) characteristics in Au/2% graphene-cobalt doped (Ca3Co4Ga0.001Ox)/n-Si structure
    (Elsevier Sci Ltd, 2015) Maril, E.; Kaya, A.; Cetinkaya, H. G.; Kocyigit, S.; Altindal, S.
    In order to good interpret of temperature dependent main electrical parameters in Au/2% graphene-cobalt (GC) doped (Ca3Co4Ga0.001Ox)/n-Si structure, forward bias current-voltage (I-V) characteristics have been investigated in the temperature range of 80340 K. The possible current-conduction mechanisms (CCMs) in this structure was also investigate in detail. The ideality factor (n), reverse saturation current (I-o), and zero-bias barrier height (Phi(Bo)) values were found as 14.5, 7.2 x 10(-6) A, 0.141 eV at 80K and 3.18, 1.7 x 10(-3) A, and 0.526 eV at 340 K, respectively. It is clear that both the value of n and Phi(Bo) are strong function of temperature. While the value of n decreases with increasing temperature, Phi(Bo) increases. In order to explain such behavior of BH the Phi(Bo) and n, Phi(Bo) vs q/2kT, Phi(Bo) vs n, and (n(-1)-1) vs q/2kT plots were drawn to obtain an evidence of a Gaussian distribution (GD) of the BHs and it shows a straight line. The mean value of BH ((Phi) over bar (Bo)) and standard deviation (sigma(s)) were found from the slope and intercept of this plot as 0.614 eV and 0.088 V, respectively. By using the modified Richardson plot, the (Phi) over bar (Bo) and Richardson constant (A*) values were obtained from the slope and intercept of this plot as 0.604 eV and 108.23 A cm(-2) K-2, respectively. It is clear that this value of A* ( = 108.23 A cm(-2) K-2) is very close to the theoretical value 112 A cm(-2) K-2 for n-Si. In conclusion, the temperature dependence of the forward bias I-V characteristics of the structure can be successfully explained on the basis of a thermionic emission (TE) mechanism with GD of the BHs. (C) 2015 Elsevier Ltd. All rights reserved.