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Öğe Electronic properties of the Al/Orange G/n-Si junction(2017-04) Güllü, Ömer; Arsel, İsmailÖğe Electrical characteristics of the Al/Congo Red (CR)/p-Si semiconductor diodes(Dumlupınar Üniversitesi, 2015-05) Güllü, Ömer; Pakma, Osman; Turut, Abdulmecit; Arsel, İsmailIn this work, we have studied the electrical characteristics of the Al/CR/p-Si MIS Schottky structures formed by coating of the organic material directly on p-Si substrate. It has been seen that the CR thin film on the p-Si substrate has indicated a good rectifying behavior. The barrier height and the ideality factor of the device have been calculated from the I-V characteristic. We have also studied the suitability and possibility of the MIS diodes for use in barrier modification of Si MS diodes. In addition, we have compared the parameters of the Al/CR/p-Si MIS Schottky diodes with those of conventional Al/p-Si MS diodes. We have observed that the b value of 0.77 eV obtained for the Al/CR/p-Si device was significantly larger than BH value of the conventional Al/p-Si MS contact. Thus, the modification of the interfacial potential barrier for metal/Si diodes has been achieved by using the CR organic interlayer. This was attributed to the fact that the CR interlayer increased the effective b by influencing the space charge region of Si. The interface-state density of the MIS diode was found to vary from 1.24×1013 eV-1 cm-2 to 2.44×1012 eV-1 cm-2.Öğe On The Profile Of Frequency Dependent Series Resistance And Interface States In Al/TiO2/p-Si (MIS) Structures(Batman Üniversitesi, 2012) Arsel, İsmailSol-gel yöntemiyle hazırlanan Al/TiO2/p-Si (MIS) yapıların iletkenlik-voltaj(G/ω-V) ve kapasitans-voltaj (C-V) karakteristiklerinin frekansa bağımlılığı oda sıcaklığında seri dirençler (Rs) ve arayüzey (Nss) durumlarına etkisi gözönüne alınarak incelenmiştir. Ölçülen kapasidans (C) ve iletkenkiğin (G/ω), frekansa ve öngerilime kuvvetle bağlı olduğu bulunmuştur. Ölçülen sığa (C) ve iletkenlik (G/ω) değerlerinin, dolma ve boşalma bölgelerinde frekansın artması ile azaldığı, Si/TiO2 arayüzeyinde Nss ölçülmüştür. Seri direnç-gerilim ( Rs-V), grafiğinde bir tepe noktası vardır ve tepe noktasının yeri, azalan frekansla birlikte ters bölgeye doğru kayar. Gerçek (MIS) kapasidans (C) ve iletkenlik (G/ω) değerlerini elde etmek amacıyla kapasidans-gerilim (C-V) ve iletkenlik-gerilim (G/ω-V) ölçümlerinin her ikisi ileri ve geri önyargılar altında seri dirençlerin etkisi için düzeltilmiştir. Frekansa bağlı kapasidans-gerilim (C-V) ve iletkenlik-gerilim (G/ω-V) ölçümleri son derece etkili elektriksel karakteristiklerin çok önemli iki parametresi MMS yapısında Rs ve Nss olduğunu gösterir.Öğe I V and C V F characteristics of aniline green N type silicon diode(İstanbul University, 2015) Özkan, Samet; Güllü, Ömer; Arsel, İsmail; Özaydın, Cihat; Pakma, Osman; Turut, AbdülmecitWe have studied the I-V, C-V and C-f characteristics of the Aniline Green (AG)/n-type Si structure. In organic/inorganic semiconductor contact applications, in order to keep the technological difficulties and unknowns to a minimum, silicon is generally chosen as the substrate semiconducting material. In this structure, deposition of organic materials on the inorganic semiconductor can generate large number of interface states at the semiconductor surface that strongly influence the electrical properties of the AG/n-Si structure. The values of the ideality factor, series resistance and barrier height obtained from two methods were compared, and it was seen that there was an agreement with each other. The downward concave curvature of the forward bias current-voltage characteristics at sufficiently large voltages is caused by the presence of the effect of series resistance. Thus, the concavity of the forward bias current-voltage characteristics increases with the increasing series resistance value. The high resistance values have given the high ideality factors. Also, the higher values of capacitance at low frequencies were attributed to the excess capacitance resulting from the interface states in equilibrium with the nSi that can follow the ac signal.Öğe Photoelectric and photocapacitance characteristics of Au/pyrene/N-Si MIS structures(Journal of Non-Oxide Glasses, 2017-04-01) Güllü, Ömer; Pakma, Osman; Özaydın, Cihat; Arsel, İsmail; Turmuş, MesutThis paper presents in-depth analysis of the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of identically prepared Au/Pyrene(C16H10)/n-Si hybrid organic-oninorganic semiconductor photovoltaic cells (total 43 diodes). The barrier heights, ideality factors and reverse bias saturation currents of all devices were extracted from the electrical characteristics. The mean barrier height, mean ideality factor and mean saturation current from I-V measurements were calculated as 0.79 ± 0.01 eV, 1.40 ± 0.08 and (1.01 ± 0.46)x10-8 A, respectively. Also, the photoelectric (I-V) and photocapacitance (C-V and conductance (G)-voltage (V)) characteristics of the Au/Pyrene/n-Si device under 100 mW/cm2 light illumination were investigated. It has been seen that the light illumination increases strongly the current, capacitance and conductance values of the device due to electron-hole charge pair generation. The C-V and G-V characteristics under illumination have shown a non-monotonic dependence of capacitance on frequency giving rise to a peak. This is attributed to the existence of electrically active traps. The open circuit voltage and short circuit current of the Au/Pyrene/n-Si device were extracted as 80 mV and 30 µA, respectively.Öğe Electrical parameters of safranine T N silicon contacts(İstanbul University, 2015) Güllü, Ömer; Arsel, İsmail; Özkan, Samet; Özaydın, Cihat; Pakma, Osman; Turut, AbdülmecitIn this work, it has been investigated current-voltage (I-V) andcapacitance-voltage-frequency (C-V-f) characteristics of the Al/SafranineT(ST)/n-Si structure. The values of the ideality factor, series resistance and barrier height calculated by using different methods were compared. It was seen that there was an agreement with each other. Also, it was seen that the barrier height value for our device was higher than one value of 0.50 eV of conventional Al/n-Si Schottky contact. The change in the barrier height value of the device was ascribed to ST thin layer modifying the effective barrier height by influencing the space charge region of the Si inorganic semiconductor. The downward concave curvature of the forward bias current-voltage characteristics at sufficiently large voltages have been attributed to the effect of series resistance. Thus, the concavity of the forward bias current-voltage characteristics increases with increasing series resistance value. It has been seen that the values of capacitance are almost independent to a certain value of frequency, after this value, the capacitance decreases with increasing frequency. The higher values of capacitance at low frequencies have been attributed to the excess capacitance resulting from the interface states in equilibrium with the n-Silicon that could follow the alternating current signal.Öğe The Current voltage and Capacitance voltage frequency characteristics of the Al methyl violet n Si diode(Türk Fizik Derneği, 2016-09) Güllü, Ömer; Arsel, İsmailÖğe Current-capacitance-voltage characteristics of the Al/methyl red/n-InP diode(2017-04) Güllü, Ömer; Arsel, İsmailÖğe Al/CuO/p-Si/Al Diyot yapısının elektriksel özellikleri(Batman Üniversitesi, 2015) Karabat, Mehmet Faruk; Arsel, İsmailBu çalışmada, Metal-yarıiletken arasına yerleştirilen ince metal-oksit (CuO) filmin diyot karakteristikleri üzerine etkisi araştırıldı. Metal yarıiletken arasına yerleştirilen CuO nano yapılı ince filmleri büyütmek için spin coating metodu kullanıldı ve bir Al/CuO/p-Si/Al diyot yapısı üretildi. Üretilen Al/CuO/p-Si/Al diyot yapısının geleneksel (I-V) karakteristiklerinden, idealite faktörü (n), engel yüksekliği (ΦB0) ve Norde fonksiyonları kullanılarak seri direnç (Rs) değerleri hesaplandı. Elde edilen filmlerin, taramalı elektron mikroskobu (SEM) görüntüleri alındı. Ayrıca CuO filmlerin optiksel özellikleri UV-VIS spektroskopisi ile incelenmiş ve buradan optiksel enerji bant aralığının 2.08 eV olduğu belirlendi. Hesaplamalara göre, üretilen diyotun doğrultucu diyot olduğu ve fotodiyot özellik gösterdiği görüldü.Öğe Statistical analysis of solar radiation models onto inclined planes for climatic conditions of Batman (Turkey)(İstanbul University, 2015) Derse, Mehmet Sait; Öztürker, Hakkı; Pakma, Nilay; Pakma, Osman; Güllü, Ömer; Arsel, İsmailSolar energy is one of the most widely used renewable energy resources in the world. A drawback, common to the photovoltaic systems (PV) is their unpredictable nature and their output cannot be accurately predicted, because, these systems are dependent on climatic conditions. Solar radiation data are the best source of information for proper design of PV systems. In this study; hourly tilted surface solar radiation is measured at different slope angles in Batman (Turkey). Selected models were compared on the basis of the statistical error tests; mean square errors (MSE), mean absolute errors (MAE) and root mean square errors (RMSE) and mean absolute percentage error (MAPE). Besides, a new equation was developed to calculate monthly average daily global solar radiation in Batman.
