Yazar "Ocak, Yusuf Selim" seçeneğine göre listele
Listeleniyor 1 - 20 / 75
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Al/metil kırmızısı/p-Si Schottky diyotların elektiriksel karakterizasyonu(2017) Ocak, Yusuf Selim; Kılıçoğlu, TahsinBu çalışmada, [100] yönelimine sahip, özdirençleri 1-10?cm olan p-Si kristalleri kullanıldı. Kloroformda oluşturulan 2,5x10-3M ve 1x10-4M konsantrasyonlarına sahip metil kırmızısı çözeltilerinin p-Si üzerine damlatılması ve çözücünün buharlaştırılması ile iki farklı Al/metil kırmızısı/p-Si Schottky engel diyotları oluşturuldu. Al/metil kırmızısı/p-Si Schottky engel diyotlarının elektronik özellikleri ve arayüzey durum yoğunluk dağılım özellikleri oda sıcaklığında akımgerilim (I-V) ve kapasite-gerilim (C-V) karakteristiklerinden (düşük ve yüksek frekans) elde edildi. Elde edilen diyotların doğrultucu özelliğe sahip oldukları gözlendi. Sırasıyla derişik ve seyreltik çözelti ile hazırlanan diyotların idealite faktörleri ve engel yükseklikleri lnI-V grafikleri kullanılarak 1.21, 0.821 eV ve 1.45, 0.828 eV olarak hesaplandı. Bu diyotların idealite faktörleri ve engel yükseklikleri ayrıca yüzey potansiyeli-gerilim ( s ? -V) grafikleri kullanılarak sırasıyla 1.21, 0.820 eV ve 2.02, 0.786 eV olarak hesaplandı. Bu sonuçlardan derişik çözelti ile hazırlanan Al/metil kırmızısı/p-Si yapının doğrultuculuğunun daha fazla olduğu ve ideale daha yakın olduğu ve bu diyot için her iki yöntemle elde edilen değerlerin birbirlerini doğruladığı görüldü. Bu sonuçlar, derişik çözelti ile hazırlanan diyotun oksit kalınlığının daha az olmasına atfedildi. Her iki diyotun yüksek (5MHz) ve düşük frekans (100kHz) kapasiteleri kullanılarak organik bileşik ile inorganik yarıiletken arayüzeylerindeki konuşlanmış arayüzey durum yoğunluklarının enerji dağılımları hesaplandı. Derişik ve seyreltik çözeltilerle hazırlanmış diyotlar için dağılımlar sırasıyla, (0.675- EV)eV ile (0.783- Ev)eV aralığında ve (0.697-Ev)eV ile (0.791- EV) eV aralığında bulundu. Ayrıca arayüzey durum yoğunluklarının Nss derişik ve seyreltik çözeltilerle hazırlanmış diyotlar için sırasıyla, (0.675- EV) eV için 3.605x1013cm-2eV-1 ile (0.783-EV) Ev için 2.542x1012cm-2eV-1 aralığında ve (0.697-EV) eV için 4.162x1012cm-2eV-1 ile (0.791-EV) eV için 1.699x1012cm-2eV?1 oldukları hesaplandı. Arayüzey durum yoğunluklarının üstel bir şekilde band ortasından valans bandın tepesine doğru arttığı görüldü.Öğe Analysis of electrical and photoelectrical properties of ZnO/p-InP heterojunction(Elsevier Science Sa, 2011) Ocak, Yusuf Selim; Kulakci, Mustafa; Turan, Rasit; Kilicoglu, Tahsin; Gullu, OmerAZnO/p-InP heterojunction has been fabricated by dc sputtering of ZnO on p-InP. It has been observed that the device has a good rectification. The electrical properties of the device such as ideality factor, barrier height, series resistance have been calculated using its current-voltage (I-V) measurements between 300 and 380K with 20K intervals. The short current density (J(sc)) and open circuit voltage (V-oc) parameters have been determined between 40 and 100mW/cm(2). The photovoltaic parameters of the device have been also determined under 100mW/cm(2) and AM1.5 illumination condition. (C) 2011 Elsevier B.V. All rights reserved.Öğe Annealing-induced characterization of sputtered V2O5 thin films and Ag/ V2O5/p-Si heterojunctions(Elsevier, 2024) Aljawrneh, Bashar; Ocak, Yusuf Selim; Albiss, Borhan AldeenV2O5 thin films were deposited on glass and p-type silicon substrates by radio frequency (RF) sputtering of a single V2O5 target. Half of the samples were annealed at 500 degrees C at room ambient for an hour. The morphological, structural, and optical properties of the thin films were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-Vis data. The results showed that while the asgrown V2O5 thin films had smooth surfaces with an amorph phase, annealed films had rougher surfaces with grains in the polycrystalline phase. It is also reported that the band gap of V2O5 thin films decreased from 2.47 to 2.37 eV. Furthermore, the electrical properties of Ag/V2O5/p-Si junctions were analyzed by current-voltage (I-V) measurements. It was presented that both Ag/V2O5/p-Si structures with as-grown and annealed V2O5 thin films had exciting rectifying behaviors. It was observed that while the barrier heights of the rectifying junctions were nearly the same, the ideality factor and series resistance values of the Ag/V2O5/p-Si device fabricated by annealed V2O5 thin film were higher than the device with as grown V2O5 thin film. Finally, the photoelectrical properties of both samples were analyzed by I-V under various light intensities. It was seen that both Ag/V2O5/pSi devices had exciting photosensing behavior. While the increase in reverse bias current values with the increase in light intensity was observed for both devices, it was seen that the device obtained by as-grown thin film had much more sensitivity to light.Öğe Barrier height enhancement of metal/semiconductor contact by an enzyme biofilm interlayer(Taylor & Francis Ltd, 2013) Ocak, Yusuf Selim; Guven, Reyhan Gul; Tombak, Ahmet; Kilicoglu, Tahsin; Guven, Kemal; Dogru, MehmetA metal/interlayer/semiconductor (Al/enzyme/p-Si) MIS device was fabricated using -amylase enzyme as a thin biofilm interlayer. It was observed that the device showed an excellent rectifying behavior and the barrier height value of 0.78eV for Al/-amylase/p-Si was meaningfully larger than the one of 0.58eV for conventional Al/p-Si metal/semiconductor (MS) contact. Enhancement of the interfacial potential barrier of Al/p-Si MS diode was realized using enzyme interlayer by influencing the space charge region of Si semiconductor. The electrical properties of the structure were executed by the help of current-voltage and capacitance-voltage measurements. The photovoltaic properties of the structure were executed under a solar simulator with AM1.5 global filter between 40 and 100mW/cm(2) illumination conditions. It was also reported that the -amylase enzyme produced from Bacillus licheniformis had a 3.65eV band gap value obtained from optical method.Öğe Co-sputtered Cu2ZnTi(S:Se)4 absorbers for thin film solar cells(Pergamon-Elsevier Science Ltd, 2020) Batibay, Derya; Ocak, Yusuf Selim; Genisel, Mustafa Fatih; Turan, RasitThin film solar cells are an exciting topic for low cost and high efficient solar cells. Owing to the high price of the indium metal in the fabrication of copper indium gallium diselenide (CIGS) solar cells, Cu2ZnSn(SSe)(4) thin films are used as a new material to reduce the cost and increase the efficiency. As an alternative absorber material for solar cell production, Cu2ZnTi(S:Se)(4) thin films were deposited by the co-sputtering method at various temperatures. During the deposition, Cu, ZnSe and Ti targets were used as metal sources. The Cu2ZnTi(S:Se)(4) thin films were annealed in H2S:Ar (1:9) atmosphere. The morphological, structural and optical properties of Cu2ZnTi(S:Se)(4) thin films was analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) Raman spectroscopy and UV-Vis-NIR spectrometer. It was seen that the thin films had good optical absorption till the infrared region and the band gap of the Cu2ZnTi(S:Se)(4) thin films were smaller than the conventional Cu2ZnSnS4 thin films. Furthermore, fabrication of a solar cell with 1.96% power conversion efficiency was reported using a Cu2ZnTi(S:Se)(4) thin film as a low cost absorber layer. (c) 2019 Elsevier Ltd. All rights reserved.Öğe CO2 sensing behavior of vertically aligned Si Nanowire/ZnO structures(Elsevier SCI LTD., 2021) Ocak, Yusuf Selim; Lamri Zeggar, Meryem; Genisel, Mustafa Fatih; Uzun, Nilufer Uslu; Aida, Mohammed SalahMetal oxide nanostructures are highly attractive for the fabrication of gas sensors due to their high surface-to-volume ratios. The design of novel structures has great importance to improve sensing behavior. Atomic layer deposited ZnO thin film on vertically aligned silicon nanowire (Si NW) arrays were used to understand the influence of etching time on CO2 sensing behavior of the SiNW/ZnO structure. The metal-assisted chemical etching method was used to realize SiNW arrays. The etching processes were performed for 5, 10, 30, and 60 min. The linear relationship between etching time and Si NW length was reported. 30 nm ZnO thin films were deposited on Si NWs by atomic layer deposition (ALD) method using diethyl Zinc and H2O as Zn and O-2 sources, respectively. The CO2 sensing properties of the SiNW/ZnO structures were examined at ambient temperature and low CO2 concentration. The testing measurement results reveal that the sensor realized on un-etched Si does not exhibit any sensitivity. While the SiNW/ZnO was sensitive to CO2, the sensor sensitivity increase with the etching time due to the increase in the specific reactive surface. Moreover, the realized sensors have a relatively low response and recovery times, in the range of 2-7 s, by comparison to the reported ones in the literature.Öğe Cross-coupling reactions in water using ionic liquid-based palladium(II)-phosphinite complexes as outstanding catalysts(Wiley, 2014) Meriç, Nermin; Aydemir, Murat; Işık, Uğur; Ocak, Yusuf Selim; Rafikova, Khadichakhan; Paşa, Salih; Kayan, Cezmi; Durap, Feyyaz; Temel, Hamdi; Zazybin, Alexey G.; 0000-0003-0899-1948; 0000-0002-6244-9327; 0000-0002-4792-8821Two new phosphinite ligands based on ionic liquids [(Ph2PO)C7H14N2Cl]Cl (1) and [(Cy2PO)C7H14N2Cl]Cl (2) were synthesized by reaction of 1-(3-chloro-2-hydoxypropyl)-3-methylimidazolium chloride, [C7H15N2OCl]Cl, with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, respectively, in anhydrous CH2Cl2 and under argon atmosphere. The reactions of 1 and 2 with MCl2(cod) (M=Pd, Pt; cod=1,5-cyclooctadiene) yield complexes cis-[M([(Ph2PO)C7H14N2Cl]Cl)(2)Cl-2] and cis-[M(Cy2PO)C7H14N2Cl]Cl)(2)Cl-2], respectively. All complexes were isolated as analytically pure substances and characterized using multi-nuclear NMR and infrared spectroscopies and elemental analysis. The catalytic activity of palladium complexes based on ionic liquid phosphinite ligands 1 and 2 was investigated in Suzuki cross-coupling. They show outstanding catalytic activity in coupling of a series of aryl bromides or aryl iodides with phenylboronic acid under the optimized reaction conditions in water. The complexes provide turnover frequencies of 57 600 and 232 800h(-1) in Suzuki coupling reactions of phenylboronic acid with p-bromoacetophenone or p-iodoacetophenone, respectively, which are the highest values ever reported among similar complexes for Suzuki coupling reactions in water as sole solvent in homogeneous catalysis. Furthermore, the palladium complexes were also found to be highly active catalysts in the Heck reaction affording trans-stilbenes. Copyright (c) 2014 John Wiley & Sons, Ltd.Öğe Deposition and Characterization of Si Substituted Cu2ZnSnS4 Thin Films(Springer, 2023) Ava, Canan Aytug; Ocak, Yusuf Selim; Celik, Omer; Asubay, SezaiThe influence of the Si substitution ratio on the structural, morphological, and optical properties of Cu2ZnSnS4 (CZTS) thin films was examined. The Cu2Zn(SixSn1-x)S-4 thin films (x = 0, 0.25, 0.50, 0.75, and 1) were deposited on soda-lime glasses by spin coating technique and annealed in a quartz tube at 550 degrees C under H2S:Ar (1:9) flows. The X-ray diffraction (XRD) patterns showed that the crystal sizes of CZTS thin film decreased rapidly from 30 nm to 19 nm after the substitution of 25% Si to the Sn sites (Cu2Zn(Si0.25Sn0.75)S-4 thin films) and increased to the same range after increasing the Si substitution ratio. It was attributed to the highest dislocation density and strain values of the film after partial Si substitution to the structure. It was also reported that the Si substitution for Cu2ZnSnS4 (CZTS) structure shifted both main XRD (from 28.51 to 28.62 degrees) and Raman peaks (from 332 to 334 cm(-1)). Furthermore, the strong influence of Si addition on the optical properties of the films was examined. It was seen that the optical band gap of CZTS increases from 1.51 to 3.22 eV with the increase in Si ratio.Öğe Diester Molecules for Organic-Based Electrical and Photoelectrical Devices(Springer, 2017) Topal, Giray; Tombak, Ahmet; Yigitalp, Esref; Batibay, Derya; Kilicoglu, Tahsin; Ocak, Yusuf SelimDiester derivatives of terephthalic acid molecules were synthesized according to the literature. Au/Diester derivatives/n-Si organic-inorganic (OI) heterojunction-type devices were fabricated, and the current-voltage (I-V) characteristics of the devices have been investigated at room temperature. I-V characteristics demonstrated that all diodes had excellent rectification properties. Primary diode parameters such as series resistance and barrier height were extracted by using semi-log I-V plots and Norde methods, and were compared. It was seen that there was a substantial agreement between results obtained from two methods. Calculated barrier height values were about the same with 0.02-eV differences that were attributed to the series resistance. Ideality factors, which show how the diode closes to ideal diodes, were also extracted from semi-log I-V plots. Thus, the modification of the Au/n-Si diode potential barrier was accomplished using diester derivatives as an interlayer. The I-V measurements were repeated to characterize the devices at 100 mW/cm(2) illumination intensity with the help of a solar simulator with an AM1.5G filter.Öğe The effect of Gd doping on the electrical and photoelectrical properties of Gd:ZnO/p-Si heterojunctions(Elsevier Science Sa, 2015) Baturay, Silan; Ocak, Yusuf Selim; Kaya, DeryaUndoped ZnO thin films, as well as 1%, 3% and 5% Gd-doped ZnO films, were deposited on p-type Si using spin coating. The structural properties of these thin films were analysed using X-ray diffraction, and the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Gd:ZnO/p-Si heterojunctions were compared with those of the undoped ZnO/p-Si heterojunctions. We found that Gd doping had a strong effect on the performance of the devices, and that the Gd:ZnO/p-Si heterojunctions formed with 1% Gd-doped ZnO were the most strongly rectifying, and had the highest barrier height and the lowest series resistance. Furthermore, the I-V measurements of the 1% Gd-doped ZnO/p-Si heterojunetion exhibited the strongest response to light. (C) 2015 Elsevier B.V. All rights reserved.Öğe Effect of Light Intensity and Temperature on the Current Voltage Characteristics of Al/SY/p-Si Organic-Inorganic Heterojunction(Springer, 2016) Imer, Arife Gencer; Ocak, Yusuf SelimAn organic-inorganic contact was fabricated by forming a thin film of sunset yellow dye (SY) on a p-Si wafer. The device showed a good rectification property, and the sunset yellow thin film modified the barrier height (Ub) of Al/p-Si contact by influencing the space charge region. The heterojunction had a strong response to the different illumination intensities and showed that it can be suitable for photodiode applications. The I-V measurements of the device were also applied in the temperature range of 100-500 K. It was seen that characteristic parameters of the device were strongly dependent upon temperature. While the value of Ub increased, the ideality factor (n) decreased with the increase in temperature. This variation was attributed to spatial inhomogeneity at the interface. The Norde function was used to determine the temperature-dependent series resistance and Ub values, and there was a good agreement with that of ln I-V data. The values of the Richardson constant (A*) and mean Ub were determined as 29.47 A cm(-2) K-2 by means of a modified activation energy plot, matching with a theoretical one, and 1.032 eV, respectively. Therefore, it was stated that the current voltage characteristic with the temperature can be explained by thermionic emission theory with Gaussian distribution of the Ub at the interface.Öğe The effect of tin doping level on the physical properties and photocatalytic degradation of cadmium oxide nanostructured film(Elsevier, 2021) İmer, Arife Gencer; Mahmood, Othman Haji; Kaya, Esra; Ocak, Yusuf SelimPure and tin (Sn) doped CdO films were deposited onto soda-lime glass via ultrasonic spray pyrolysis (USP) method with Sn concentrations of 1, 2 and 3%. The effect of doping level on the structural, morphological and optical properties of the films was explored by using several diagnostic techniques including X-ray diffraction, atomic force microscopy, UV-Vis spectroscopy and Hall effect methods. The doping level in the CdO film affects the photocatalytic performance of the nanostructured films. It has been declared that the physical properties of the highly conducting and transparent nanostructured CdO films can be modified/controlled by tin doping for optoelectronic applications. (c) 2021 Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the International Congress on Semiconductor Materials and Devices, ICSMD2018Öğe Effects of the r-GO doping on the structural, optical and electrical properties of CdO nanostructured films by ultrasonic spray pyrolysis(Springer, 2020) Imer, Arife Gencer; Gulcan, Mehmet; Celebi, Metin; Tombak, Ahmet; Ocak, Yusuf SelimUndoped and reduced graphene oxide (r-GO)-doped CdO films were prepared via the ultrasonic spray pyrolysis method with weight ratios of 1, 3 and 5% onto substrates. The successfully prepared films were characterized to understand the influence of r-GO dopant content on the morphological, structural, electrical and optical properties of the films by several diagnostic techniques. XRD measurement confirms that all the films were polycrystalline in the cubic phase of CdO with the preferred orientation (111). The optical band gap of the films decreases with the increase in doping amount. The r-GO@CdO nanostructured films were used as an interfacial layer to fabricate the heterojunction device and to investigate their electrical properties using current-voltage and capacitance-voltage measurements in the dark. The rectification properties of the studied devices increase with the r-GO dopant amount. The obtained results indicate that the r-GO content in the CdO films is responsible for the modification of physical properties of electronic device.Öğe Electrical and optical properties of Cu2ZnSnS4 grown by a thermal co-evaporation method and its diode application(Elsevier Sci Ltd, 2014) Tombak, Ahmet; Ocak, Yusuf Selim; Genisel, Mustafa Fatih; Kilicoglu, TahsinCu2ZnSnS4 (CZTS) is low cost and constitutes non-toxic materials abundant in the earth crust. Environment friendly solar cell absorber layers were fabricated by a thermal co-evaporation technique. Elemental composition of the film was stated by energy dispersive spectroscopy (EDS). Some optical and electrical properties such as absorption of light, absorption coefficient, optical band gap charge carrier density, sheet resistance and mobility were extracted. Optical band gap was found to be as 144 eV, besides, charge carrier density, resistivity and mobility were found as 2.14 x 10(19) cm(-3), 8.41 x 10(-4) Omega cm and 3.45 x 10(2) cm(2) V-1 s(-1), respectively. In this study Ag/CZTS/n-Si Schottky diode was fabricated and basic diode parameters including barrier height, ideality factor, and series resistance were concluded using current-voltage and capacitance-voltage measurements. Barrier height and ideality factor values were found from the measurements as 0.81 eV and 4.76, respectively, for Ag/CZTS/n-Si contact. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Electrical and photoelectrical behaviour of heterojunctions based on novel oligomeric metal complexes(Wiley, 2015) Atlan, Metin; Ocak, Yusuf Selim; Paşa, Salih; Temel, Hamdi; Tombak, Ahmet; Kılıçoglu, Tahsin; Akkılıç, Kemal; Aydemir, Murat; 0000-0002-4238-5012; 0000-0002-4792-8821; 0000-0002-9997-1653; 0000-0002-7150-6522Naringenin-based Schiff base ligands with 4-aminobenzoic hydrazide were obtained as a unilateral form (L-1). The ligand was oligomerized by oxidative polycondensation reaction with NaOCl as an oxidant in an aqueous alkaline medium at 90 degrees C to form a functional oligomer (L-2), and its transition metal complexes such as those with Cu(II), Ni(II) and Zn(II) were prepared. The monomer and the oligomeric compounds were characterized using various techniques. Optical and electrical properties of the complexes were also investigated. All compounds showed indirect band gaps and they can be accepted as being in the semiconductor class. Organic-inorganic hybrid devices were obtained using n-Si inorganic semiconductor and the complexes. The characteristic parameters of the devices were determined using current-voltage (I-V) and capacitance-voltage measurements in the dark. Photoelectrical properties of the devices were investigated using I-V measurements under a solar simulator with an AM1.5 global filter. Copyright (C) 2015 John Wiley & Sons, Ltd.Öğe Electrical and photoelectrical characterization of a TTF/p-InP organic–inorganic heterojunction(Microelectronic Engineering, 2014) Kilicoglu, Tahsin; Tombak, Ahmet; Ocak, Yusuf Selim; Aydemir, MuratTetrathiafulvalene (TTF) with C6H4S4 molecular formula was used in the fabrication of organic inorganic (OI) heterojunction. The Al/TTF/p-InP/Au-Zn structure was fabricated by forming a thin TTF organic semiconductor on p-InP inorganic semiconductor and evaporating of Al metal on the film. The characteristic parameters of the device were determined by using current-voltage (I-V) and capacitance voltage (C-V) measurements. Interface state density distribution was calculated from the I-V characteristics. The I-V characteristics of the device were also examined at 100 mW/cm(2) illumination intensity by the help of a solar simulator with AM1.5 global filter. (C) 2014 Elsevier B.V. All rights reserved.Öğe Electrical and photoelectrical characterization of an organic-inorganic heterojunction based on quinoline yellow dye(Elsevier Sci Ltd, 2015) Ugur, Ali; Imer, Arife Gencer; Ocak, Yusuf SelimAn organic-inorganic contact was fabricated by forming a thin film of quinoline yellow dye (QY) on a p-Si wafer and evaporating Al metal on the film. The current-voltage (I-V) and capacitance-voltage (C-V) measurements of Al/QY/p-Si heterostructure were applied in dark and room temperature to calculate the characteristic parameters of diode like ideality factor, barrier height and series resistance. Ideality factor and barrier height values were found as 1.23 and 0.87 eV from I-V data, respectively. The series resistance value of the device was determined as 1.8k Omega by using modified Norde function. The C-V measurements were carried out at different frequencies and it was seen that capacitance value decreased with increasing frequency. Interface state density distribution was calculated by means of I-V measurement. In addition the optical absorption of thin QY film on glass was measured and optical band gap of the film was found as 2.73 eV. Furthermore, I-V measurements of Al/QY/p-Si/Al were taken under illumination between 40 and 100 mW/cm(2). It was observed that reverse bias current of the device increased with light intensity. Thus, the heterojunction had a strong response to the light and it can be suitable for electrical and optoelectronic applications like a photodiode. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Electrical and photoelectrical characterization of Au/n-Si diode with sputtered ZrO2 interlayer(Springer, 2023) Obaid, Masoud Giyathaddin; Ocak, Yusuf Selim; Albiss, Borhan Aldeen; Benhaliliba, MostefaZrO2 thin films were deposited on n-Si and quartz substrates by a reactive sputtering technique. The morphological and optical characterization of a sputtered ZrO2 thin film revealed a highly smooth surface with 1.5 nm roughness and optical band gap value of 5.7 eV. An Au/ZrO2/n-Si metal–insulator-semiconductor (MIS) structure was obtained by evaporation of the Au on ZrO2/n-Si structure. The electrical properties analyzed by current–voltage (I-V) measurements in the dark showed that the device had 5. 094 ideality factor, 0.808 eV barrier height, and 50 Ω series resistance values. The C-V measurements showed that the device could not follow the AC signals at higher frequencies owing to the interface states, and the barrier height value calculated using C-V data (0.916 eV) is higher than the one obtained from the I-V plot. The photoelectrical parameters were determined by I-V measurements at various light intensities. The findings proved that the photoelectrical parameters of the MIS device had a photosensing behavior.Öğe Electrical and photoelectrical characterization of organic-inorganic heterostructures based on Ru-N-heterocyclic carbene complexes(Elsevier Gmbh, 2018) Yasar, Sedat; Cekirdek, Suzan; Binbay, Nil Ertekin; Tombak, Ahmet; Ocak, Yusuf Selim; Arslan, Nevin; Baysal, Akin1,3-Bis(2-morpholinethyl)benzimidazoliumtrichlorido(eta(6)-p-cymene)-ruthenate(11), 2, was synthesized and characterized by NMR spectroscopy and micro analysis. The organic -inorganic heterojunctions were fabricated by using n-type Si wafer and a series of Ru-N-heterocyclic carbene complexes, 3-5, bearing sterically hindered aryl groups were documented for the first time. The thin films of the complexes are deposited on n-Si substrates using spin coating. Current-voltage (I-V) measurements of the devices in dark and illuminated environments were analyzed to determine electrical parameters of devices. Furthermore, the photoelectrical properties of the structures were investigated examined using I-V measurements under a solar simulator. Complexes 3 and 5 showed very low series resistance resulting in high rectification ratios which are promising results for the future electronic and photoelectronic applications. (C) 2017 Published by Elsevier GmbH.Öğe Electrical and photoelectrical properties of Ag/n-type Si metal/semiconductor contact with organic interlayer(Elsevier Science Sa, 2015) Ozerden, Enise; Ocak, Yusuf Selim; Tombak, Ahmet; Kilicoglu, Tahsin; Turut, AbdulmecitElectrical and photoelectrical features of Metal/Organic Interlayer/Inorganic Semiconductor (MIS) Schottky device were investigated by using current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. For this purpose, 9,10-dihydrobenzo[a]pyrene-7(8H)-one (9,10-H2BaP) thin film was used as organic interlayer between Ag metal and n-Si semiconductor. Firstly, optical properties of the organic thin film were determined from optical absorption spectrum, and its optical band gap was found to be 3.73 eV. Then, the electrical parameters of the Ag/9,10-H2BaP/n-Si diode such as ideality factor (n), barrier height (Phi(b(I-V))), diffusion potential (V-d), barrier height (Phi(b(C-V))) and carrier concentration (N-d) were calculated from I-V and C-V characteristics at room temperature. The Fb values obtained from both measurements were compared with each other. Besides, the effect of light on I-V measurements of the structure was examined at illumination intensities ranging from 40 to 100 mW/cm(2) with 20 mW/cm(2) intervals using a solar simulator with AM1.5 filter. Light sensitivity, open circuit voltage (V-OC) and short circuit current (I-SC) parameters of Ag/9,10-H2BaP/n-Si structure were calculated from under light measurements. (C) 2015 Elsevier B.V. All rights reserved.
