Browsing by Author "Altindal, S."

Now showing 1 - 3 of 3

Temperature Dependence of Characteristic Parameters of The Au/C20H12/N-Si Schottky Barrier Diodes (SBDS) in The Wide Temperature Range
(2017) Moraki, K.; Bengi, S.; Zeyrek, S.; Bulbul, M. M.; Altindal, S.; https://orcid.org/0000-0002-3348-0712; HPH-9613-2023
Au/C20H12/n-Si SBD was fabricated and its characteristic parameters such as reverse-saturation current (I-o), ideality factor (n), zero-bias barrier height (I broken vertical bar(bo)), series and shunt resistances (R-s, R-sh) were found as 1.974 x 10(-7) A, 6.434, 0.351 eV, 30.22 a"broken vertical bar and 18.96 ka"broken vertical bar at 160 K and 1.061 x 10(-6) A, 2.34, 0.836 eV, 5.82 a"broken vertical bar and 24.52 ka"broken vertical bar at 380 K, respectively. While the value of n decreases with increasing temperature, I broken vertical bar(bo) increases. The change in I broken vertical bar(bo) with temperature is not agreement with negative temperature coefficient of forbidden band-gap of semiconductor (Si). Thus, I broken vertical bar (bo) versus n, I broken vertical bar (bo) and (n(-1) - 1) versus q/2kT plots were drawn to obtain an evidence of a Gaussian distribution (GD) of the BHs and all of them have a straight line. The mean value of BH () was found as 0.983 eV from the intercept of I broken vertical bar (bo) versus n plot (for n = 1). Also, the value of and standard deviation (sigma(s)) were found as 1.123 eV and 0.151 V from the slope and intercept of I broken vertical bar(bo) versus q/2kT plot. By using the modified Richardson plot, the and Richardson constant (A*) values were obtained as 1.116 eV and 113.44 A cm(-2) K-2 from the slope and intercept of this plot, respectively. It is clear that this value of A* (=113.44 A cm(-2) K-2) is very close to their theoretical value of 112 A cm(-2) K-2 for n-Si. In addition, the energy density distribution profile of surface states (D-it) was obtained from the forward bias I-V data by taking into account the bias dependent of the effective barrier height (I broken vertical bar (e) ) and ideality factor n(V) for four different temperatures (160, 200, 300, and 380 K). In conclusion, the I-V-T measurements of the Au/C20H12/n-Si SBD in the whole temperature range can be successfully explained on the basis of thermionic emission (TE) theory with GD of the BHs.
The Capacitance/Conductance And Surface State Intensity Characteristics Of The Al/(Cmat)/P-Si Structures
(Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-02-01) Cetinkaya, H. G.; Bengi, S.; Sevgili, O.; Altindal, S.
To determine the Al/(CMAT)/p-Si structure's admittance analysis, capacitance/conductance versus frequency (C/G-V-f) data was obtained in the 3 kHz-3 MHz and -2/4 V ranges at room temperature. The powder form of CeMgAl11O19: Tb (CMAT) was thermally evaporated onto the front of p-Si wafer at 10-6 Torr as interfacial layer. From the Nicollian and Brews method, voltage-dependent spectra of Rs were derived for various frequencies. The parallel conductance and low-high frequency capacitance (CLF-CHF) techniques, respectively, were used to determine the voltage and frequency dependent spectra of Nss and their lifetime (tau). Surface states (Nss), which are identified by admittance measurements, emerge at the M/S interlayer because of high capacitance and conductance values at low frequencies. This can also be explained by the Nss's ability to track ac signals well at lower frequencies. The normalized parallel conductance versus frequency (Gp/omega-f) plot under various biases shows a peak because of Nss existence. x-ray diffractometer (XRD) was used for structural investigation and the average crystal size (D) of the nanocrystals (CMAT) was found to be less than 0.34 nm by using the Debye-Scherer's equation.
The Capacitance/Conductance And Surface State Intensity Characteristics Of The Al/(CMAT)/p-Si Structures
(PHYSICA SCRIPTA, 2024-01-24) Cetinkaya, H. G.; Bengi, S.; Sevgili, O.; Altindal, S.
To determine the Al/(CMAT)/p-Si structure's admittance analysis, capacitance/conductance versus frequency (C/G-V-f) data was obtained in the 3 kHz-3 MHz and -2/4 V ranges at room temperature. The powder form of CeMgAl11O19: Tb (CMAT) was thermally evaporated onto the front of p-Si wafer at 10-6 Torr as interfacial layer. From the Nicollian and Brews method, voltage-dependent spectra of Rs were derived for various frequencies. The parallel conductance and low-high frequency capacitance (CLF-CHF) techniques, respectively, were used to determine the voltage and frequency dependent spectra of Nss and their lifetime (tau). Surface states (Nss), which are identified by admittance measurements, emerge at the M/S interlayer because of high capacitance and conductance values at low frequencies. This can also be explained by the Nss's ability to track ac signals well at lower frequencies. The normalized parallel conductance versus frequency (Gp/omega-f) plot under various biases shows a peak because of Nss existence. x-ray diffractometer (XRD) was used for structural investigation and the average crystal size (D) of the nanocrystals (CMAT) was found to be less than 0.34 nm by using the Debye-Scherer's equation.