Browsing by Author "Duman, Songuel"

Now showing 1 - 2 of 2

The Effects of Electron Irradiation on the Current-Voltage and Capacitance-Voltage Measurements of Sn/P-GaAs Diodes
(Pergamon-Elsevier Science Ltd, 2022) Duman, Songuel; Kaya, Fikriye Seyma; Dogan, Huelya; Turgut, Gueven; Sahin, Yilmaz
In this study 11 (eleven) Sn/p-GaAs/Au diodes were identically fabricated. Au and Sn metals were used in order to fabricate the ohmic and rectifier contacts, respectively. The effect of electron irradiation of high electron energy of 6, 12, 15 and 18 MeV and low electron fluence of 1 x 10(12) electrons/cm(2) on the various parameters such as barrier height (BH), ideality factor (IF), series resistance (R-s), and rectification ratio (RR), acceptor concentration (N-a), diffusion potential (V-d) obtained from current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Sn/p-GaAs/Au diodes was evaluated. The BH value of one (D2) of the unirradiated 11 Sn/p-GaAs/Au diodes was calculated as 0.82 eV, 0.86 eV and 0.94 eV from ln(I)-V characteristics according to the thermionic emission (TE) theory, modified Norde's functions, and C-V characteristics, respectively. The BH values calculated ln(I)-V and Norde's functions were found to be very close to each other. The values of RR, IF, and BH of D2 diode calculated from ln(I)-V according to TE theory were calculated as 1 x 10(6), 1.09 and 0.82 eV, 1 x 10(6), 1.06 and 0.81 eV, 1 x 10(6), 1.09 and 0.82 eV, 1 x 10(6), 1.12 and 0.83 eV, 1 x 10(6), 1.13 and 0.82 eV for before and after 6, 12, 15 and 18 MeV electron irradiation, respectively. The R-s value of unirradiated and 6, 12, 15 and 18 MeV electron irradiated D2 diode was calculated from Norde's function was calculated 29, 30, 30, 27, and 26 omega, respectively. Since these parameters remain nearly unchanged after electron irradiation, it can be said that electron radiation has no significiant effect on ln (I)-V characteristics and the Sn/p-GaAs/Au diodes are insensitive to high-energy electron-irradiation.
Neural Network Estimations of Annealed and Non-Annealed Schottky Diode Characteristics at Wide Temperatures Range
(Elsevier Sci Ltd, 2022) Dogan, Huelya; Duman, Songuel; Torun, Yunis; Akkoyun, Serkan; Dogan, Seydi; Atici, Ugur
In this study, Artificial Neural Network (ANN) model has been proposed to characterize the annealed and the non-annealed Schottky diode from experimental data. The experimental current values of Ni/n-type 6H-SiC Schottky diode for the voltages applied to the diode terminal starting from 80 K with 20 K steps up to 500 K temperature were measured for both non-annealed and annealed Schottky diodes. The applied voltage has been varied starting from -2 V with 10 mV steps up to +2 V for each temperature value. The modeling performance has been assessed according to the varying number of neurons in the hidden layer, starting from 5 to 50 neurons, thereafter the optimum number of neurons has been obtained for both annealed and non-annealed ANN models. The minimum Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) indices values for both annealed and non-annealed diodes have been obtained with 40 neurons for both the training and test phase.