Abdulkadir Korkut | Yuzuncu Yil University (original) (raw)

Conference Presentations by Abdulkadir Korkut

Bromothymol blue (BTB) with the molecular formula of C 27 H 28 Br 2 O 5 S was grown onto p-Si sub... more Bromothymol blue (BTB) with the molecular formula of C 27 H 28 Br 2 O 5 S was grown onto p-Si substrate to fabricate heterojunction by spin coating technique. The current voltage (I-V) measurements of diode were carried out in dark and under different illumination intensity at room temperature. The photoelectrical properties of heterojunction based on BTB were investigated using the illumination intensity dependent I-V data. The results showed that photo current of diode increases with the increase in light intensity. Also, the electrical parameters of device were determined via I-V, and capacitance-voltage (C-V), conductance-voltage (G-V) measurements at different frequencies. It is observed that the excess capacitance is created at low frequencies due to the contribution of interface states charge which can follow the alternative current signal to capacitance. It is stated that, both the electrical & photoelectrical parameters of diode can be changed, and also the performance of the device could be affected by the organic thin film interlayer.

Papers by Abdulkadir Korkut

International Journal of Thin Films Science and Technology, 2016

In this work, we studied the effect of air-exposed layer on the current-voltage (I-V) capacitance... more In this work, we studied the effect of air-exposed layer on the current-voltage (I-V) capacitance versus voltage (C-V) and capacitance versus frequency (C-f) characteristics of Cu/n-Si/Al Schottky diodes. We fabricated with and without thin oxide layer Cu/n-Si/Al diodes. Firstly, n-Si wafer having (100) oriented and 15 Ω.cm resistivity was cut into eight pieces labeled Diode 1 (D1) to Diode 8 (D8). We formed the referents Cu/n-Si/Al Schottky diode (D1) which has not exposed to air. Rest of the samples, before formation of Schottky contact, was exposed to clean air at the room temperature for 2, 4, 8, 16, 32, 48 and 64 days. Therefore, Schottky contact with native oxide layer on the polished n-Si surface was obtained. From ln(I)-V plot of the Cu/n-Si/Al diodes, ideality factor (n), barrier height (eb), the interface state density of the Schottky junctions (Nss), saturation current (I0) and series resistance (RS) were calculated. In addition, same parameters were verified using both Cheung functions and C-2-V characteristics. Moreover, the interface state densities of the Schottky junctions versus energy Nss-(Ec-Es) also was calculated and plotted. What causes to excess capacity of the space charge have also been investigated. While the value of ideality factor and series resistance increased with increasing exposure time to air, the barrier height eΦB value of the Schottky diode with oxide layer is smaller than those without oxide layer. This is attributed to formation oxide layer occurring between interfaces of metal and semiconductor surface.

Microelectronic Engineering, 2018

In this study, a group of new series resistance has been derived using Cheung functions. In contr... more In this study, a group of new series resistance has been derived using Cheung functions. In contrast to the traditional approximation, new serial resistance formulae result in very exceptional value from the conventional serial resistance values for both cases, the forward bias and the reverse bias. These new serial resistance formulae exhibit a stable behavior. Besides, the relation between R Ns1-I, R Ns2-I, R Ns1-V bi and R Ns2-V bi could be shown easily. It is enough to take the current matching of the integer values of the built-in potential.

Surface Review and Letters, 2017

It is well known that the semiconductor surface is easily oxidized by air-media in time. This wor... more It is well known that the semiconductor surface is easily oxidized by air-media in time. This work studieds the characterization of Schottky diodes and changes in depletion capacitance, which is caused by air exposure of a group of Cu/n-Si/Al Schottky diodes. First, data for current-voltage and capacitance-voltage were a Ren, and then ideality factor, barrier height, built-in potential ([Formula: see text], donor concentration and Fermi level, interfacial oxide thickness, interface state density were calculated. It is seen that depletion capacitance was calculate; whereafter built-in potential played an important role in Schottky diodes characteristic. Built-in potential directly affects the characteristic of Schottky diodes and a turning point occurs. In case of forward and reverse bias, depletion capacitance versus voltage graphics are matched, but in an opposite direction. In case of forward bias, differential depletion capacitance begins from minus values, it is raised to first ...

Chinese Physics Letters, 2007

Surface Review and Letters, 2017

It is well known that the semiconductor surface is easily oxidized by air-media in time. This wor... more It is well known that the semiconductor surface is easily oxidized by air-media in time. This work studieds the characterization of Schottky diodes and changes in depletion capacitance, which is caused by air exposure of a group of Cu/n-Si/Al Schottky diodes. First, data for current-voltage and capacitance-voltage were a Ren, and then ideality factor, barrier height, built-in potential (V bi Þ, donor concentration and Fermi level, interfacial oxide thickness, interface state density were calculated. It is seen that depletion capacitance was calculate; whereafter built-in potential played an important role in Schottky diodes characteristic. Built-in potential directly a®ects the characteristic of Schottky diodes and a turning point occurs. In case of forward and reverse bias, depletion capacitance versus voltage graphics are matched, but in an opposite direction. In case of forward bias, di®erential depletion capacitance begins from minus values, it is raised to ¯rst V bi , then reduced to second V bi under the minus condition. And it sharply gones up to positive apex, then sharply falls down to near zero, but it takes positive values depending on DC voltage. In case of reverse bias, di®erential depletion capacitance takes to small positive values. In other respects, we see that depletion characteristics change considerably under DC voltage.

SDÜ Fen Bilimleri Enstitüsü Dergisi, 2017

In this study, the photovoltaic device application of bromothymol blue (BTB) as an organic interl... more In this study, the photovoltaic device application of bromothymol blue (BTB) as an organic interlayer has been reported. After Al back contact fabrication on the surface of the chemically cleaned substrate by thermal evaporation method, the organic interlayer has been grown on pSi substrate via spin coating technique. Al top contacts
have been formed on this organic thin film to finalize the device constructions. The different illumination intensities were exposed to the prepared sample for the enhancement in the photovoltaic properties of device. The fundamental photovoltaic parameters such as open circuit voltage (Voc), short circuit current (Isc) and output
power (P) were determined for the device under different illuminations. The photocurrent and the photo voltage have been increased with the increasing in illumination intensity. The dependence of the capacitance on the voltage at high and low frequency has been also reported for the studied device. Consequently, it has been confirmed that the illumination intensity has an important influence on the photovoltaic parameters of the
device.

The Fermi energy, cyclotron energy and cyclotron effective mass of degenerate electron gas in a s... more The Fermi energy, cyclotron energy and cyclotron effective mass of degenerate electron gas in a size quantized semiconductor thin films with non-parabolic energy bands are studied. The influences of quantizing magnetic field on these quantities in two-band approximation of Kane model are investigated. It is shown that the Fermi energy oscillates in a magnetic field. The period and positions of these oscillations are found as a function of film thickness and concentration of electrons. Cyclotron energy and cyclotron effective mass are investigated as a function of film thickness in detail. The results obtained here are compared with experimental data on GaAs quantum wells.

In this work, the heat capacity in dimensionally quantized semiconductor thin films with Kane's d... more In this work, the heat capacity in dimensionally quantized semiconductor thin films with Kane's dispersion law is investigated. Under certain conditions, quantum size effect occurs, depending on the thickness of the thin film, the concentration of conductive electrons, and the non-parabolicity parameters. In thin films having non-parabolic energy spectrum in degenerate electron gas, the film thickness depends on the subband number and the concentration. Therefore, heat capacity takes the form of the saw toothwise and changes as non-monotonous.

International Journal of Thin Films Science and Technology, 2016

Microelectronic Engineering, 2018

Surface Review and Letters, 2017

Chinese Physics Letters, 2007

Surface Review and Letters, 2017

It is well known that the semiconductor surface is easily oxidized by air-media in time. This wor... more It is well known that the semiconductor surface is easily oxidized by air-media in time. This work studieds the characterization of Schottky diodes and changes in depletion capacitance, which is caused by air exposure of a group of Cu/n-Si/Al Schottky diodes. First, data for current-voltage and capacitance-voltage were a Ren, and then ideality factor, barrier height, built-in potential (V bi Þ, donor concentration and Fermi level, interfacial oxide thickness, interface state density were calculated. It is seen that depletion capacitance was calculate; whereafter built-in potential played an important role in Schottky diodes characteristic. Built-in potential directly a®ects the characteristic of Schottky diodes and a turning point occurs. In case of forward and reverse bias, depletion capacitance versus voltage graphics are matched, but in an opposite direction. In case of forward bias, di®erential depletion capacitance begins from minus values, it is raised to ¯rst V bi , then reduced to second V bi under the minus condition. And it sharply gones up to positive apex, then sharply falls down to near zero, but it takes positive values depending on DC voltage. In case of reverse bias, di®erential depletion capacitance takes to small positive values. In other respects, we see that depletion characteristics change considerably under DC voltage.

SDÜ Fen Bilimleri Enstitüsü Dergisi, 2017