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This work describes the optical, morphological and structural characterizations of graphene oxide (GO) layers grown by drop casting and annealing process. UV-vis optical measurement shows that the values of direct and indirect optical gap energy of the GO film are 3.89 eV and 3.21 eV, respectively. The graphene oxide (GO) layer has been placed in the metal/ interlayer /semiconductor (MIS) diodes (total 17 devices) on p-Si wafers. The graphene oxide diodes give a better barrier height enhancement as compared with the conventional diodes. The value of homogeneous barrier height for Al/GO/p-Si MIS junctions was extracted as 0.74 eV. The diodes were also investigated under 300 watt light illumination for photovoltaic applications. Additionally, interfacial properties of the MIS diode with GO interlayer were determined. It has been seen that the capacitance of the device changes as a function of gate voltage and signal frequency from the capacitance-frequency measurements. It has also been reported that the interfacial trap charges reduce the capacitance with increasing frequency values., This study is supported by Republic of Turkey-Prime Ministry State Planning organization (DPT) (Project Number: 2010K120610, Batman University Central Research Laboratory).

Bu çalışmada π bağları açısından zengin organik molekülün (Nigrosin (NIG)) optik özellikleri UV-Vis yöntemiyle belirlendi. Cam altlık üzerinde damlatma yöntemi ile büyütülen NIG ince tabakasının direkt yasak enerji değerleri; 1,42 eV (Q bandı) ve 2,94 eV (B bandı) olarak rapor edildi. Oluşturulan referans Al/p-Si ve Al/NIG/p-Si Metal/Organik aratabaka/Yarıiletken (MIS) yapılarının I-V ölçümleri sonunda tüm yapıların doğrultucu özelliğe sahip oldukları gözlemlendi. Oda sıcaklığında alınan I-V ölçümleri kullanılarak yapıların karakteristik diyot özellikleri belirlendi. Burada Al/NIG/p-Si diyotunun kapasitör özelliği, C-V ölçümleri alınarak incelendi ve yapılan hesaplamalar sonucunda bazı diyot parametreleri elde edildi. Elde edilen sonuçlar, π bağları açısından zengin olan NIG gibi organik malzemelerin elektronik sahasında kullanılabileceğini gösterdi.

High-energy radiation penetrates the metal-semiconductor (MS) interface and causes damage deep below the interface. Low-energy radiation causes severe lattice damage in the form of vacancies, interstitials and defect complexes at the near interface of the device. The one kind of the radiation is electron beam which is accelerated. Mills was the first to recognize that electrons with energy of 1 MeV would possess enough energy to displace an atom from its lattice position. This observation has led to the increased use of electron accelerators in radiation damage studies. This use has been motivated by two important facts. First, electron bombardment experiments permit the determination of the energy required to remove an atom from its initial position. This is done by increasing the energy of the electrons until an observable change in a radiation-sensitive property is seen. The second important basis for the use electrons lie in the fact that as long as the energy of the electrons is close to the displacement threshold, it is presumed, that only single Frenkel pairs are formed. Thus, many radiation-induced phenomena can be analyzed in terms of a single vacancy and/or interstitial atom, and one avoids the complication attendant upon the generation of complex damage regions presumed to occur in heavy-charged particle irradiation. In the present paper, a lead/rhodamine-101(Rh101)/p-Si metal/organic interlayer/ semi-conductor diode was fabricated and the effect of 6 MeV-electron irradiation on the electrical characteristics of the diode structure was investigated. It was seen that after electron irradiation the barrier height values, the series resistance values and ideality factors increased. Furthermore, it was seen that the capacitance values increased after electron irradiation. This was attributed to the change in dielectric constant at the interface and/or to decrease in the net ionized dopant concentration and the interface states. The degradation of the diode properties may be due to the introduction of electron irradiationinduced interfacial defects via displacement damage.

The radiation response of metal-semiconductor (MS) contacts has been found to alter significantly when the structures are exposed to pre-irradiation processes at determined doses. Radiation doses greater than a kilogray exposure may cause strong changes on the electrical characteristics of MS structures. It has been also shown that the particle or gamma irradiations induce defects in the band gap which affects the free carrier concentration and leads to an increase and decrease of barrier height in p-type and n-type semiconductors, respectively. The knowledge of the influence of radiation damage on the Schottky barrier diodes (SBDs) performance is a fundamental field of research, having technological relevance for many applications in the semiconductor electronic devices. Hence, it is very much essential to evaluate the effect of irradiation and identify the degradation mechanism to understand the failure mechanisms. In this work, we have investigated the electrical parameters of the Sn/p-Si Schottky barrier diodes by using I-V and C-V characteristics under γ-irradiation at room temperature. The basic diode parameters such as ideality factor, barrier height, series resistance and reverse saturation current were extracted from electrical measurements as a function of the irradiation dose. The results indicated that γ-irradiation induced an increase in the effective Schottky barrier height extracted from both I-V and C-V measurements. Also, it was seen that ideality factor increased with the increasing γ-irradiation doses. We have also observed that the reverse bias current of the Sn/Si contact exceedingly decreased with increasing irradiation dose with low energy (60 keV). The basic results as related to the gamma irradiation have been indicated that this device may have applications as radiation sensors in order to detect the low energy gamma radiation.

This work includes fabrication and electrical characterization of Metal/Interlayer/Semiconductor (MIS) structures with methyl violet organic film on p-InP wafer. Metal(Ag)/ Interlayer (methyl violet =MV)/Semiconductor(p-InP) MIS structure presents a rectifying contact behavior. The values of ideality factor (n) and barrier height (BH) for the Ag/MV/p-InP MIS diode by using the current-voltage (I-V) measurement have been extracted as 1.21 and 0.84 eV, respectively. It was seen that the BH value of 0.84 eV calculated for the Ag/MV/p-InP MIS structure was significantly higher than the value of 0.64 eV of Ag/p-InP control contact. This situation was ascribed to the fact that the MV organic interlayer increased the effective barrier height by influencing the space charge region of inorganic semiconductor. The values of diffusion potential and barrier height for the Ag/MV/p-InP MIS diode by using the capacitance-voltage (C-V) measurement have been extracted as 1.21 V and 0.84 eV, respectively. The interface-state density of the Ag/MV/p-InP structure was seen to change from 2.57×1013 eV-1cm-2 to 2.19×1012 eV-1cm-2

The aim of the study is to develop a more economic and easier method which has lower temperature in obtaining ZrO2 thin films contrary to the literature. In this study, we produced thin ZrO2 films on amorphous glass substrates through the wet chemical method by using different chemicals with the same starting reactive. X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy measurements of the produced films were conducted and the results were compared. The best method has been identified at the end of the analysis and it has been observed that the features of the films produced with this method have given better results than both the films produced by using different reagents and the films produced in literature.

In 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.

The performance of a photovoltaic (PV) system depends on both the module technology and also on the outdoor conditions. The impact of solar radiation, ambient and module temperature, humidity, dust and ventilation can strongly affect energy production of the PV system. In this study, three 2.2 kW grid-connected PV generation systems under the outdoor conditions are analyzed in Batman (Turkey). The types of modules examined in this study are: monocrystalline silicon, polycrystalline silicon and amorphous silicon. The monthly and annual performance ratios have been calculated for the three modules and a comparison is presented here. Optimization potentials of Batman are also discussed.

Solar 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.

In 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.

We 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.

Electrical characteristics of Co/n-Si Schottky barrier diodes are analysed by current-voltage (I – V) and capacitance-voltage (C – V) techniques at room temperature. The electronic parameters such as ideality factor, barrier height and average series resistance are determined. The barrier height 0.76eV obtained from the C – V measurements is higher than that of the value 0.70eV obtained from the I – V measurements. The series resistance RS and the ideality factor n are determined from the d ln(I)/dV plot and are found to be 193.62Ω, and 1.34, respectively. The barrier height and the RS value are calculated from the H(I) – I plot and are found to be 0.71 eV and 205.95Ω. Furthermore, the energy distribution of the interface state density is determined from the forward bias I – V characteristics by taking into account the bias dependence of the effective barrier height. The interface state density Nss ranges from 6.484 × 1011 cm−2eV−1 in (EC – 0.446) eV to 2.801 × 1010 cm−2eV−1 in (EC – 0.631) eV, of the Co/n-Si Schottky barrier diode. The results show the presence of a thin interfacial layer between the metal and the semiconductor.

Bu çalışmada yarıiletken teknolojisinde verimli bir şekilde kullanılabilecek nanometre kalınlıklı Au/n-GaAs Schottky diyotlara ait akım-gerilim (I-V), kapasite-gerilim (C-V) gibi elektriksel karakteristikler numune sıcaklığına ve ısıl tavlama sıcaklığına bağlı olarak detaylı bir şekilde ele alındı. Diyotlarda meydana gelen taşıyıcı iletim mekanizması, tekli ve ikili Gauss dağılımı temelinde incelendi. Ayrıca sıcaklığın fonksiyonu olarak elde edilen diyot parametreleri üzerine, engel metali kalınlığının ve hidrojen ile yüzey hazırlamanın etkileri araştırıldı. Hidrojen ortamında yapılan tavlama işleminin metal-yarıiletken yüzeyini pasive ederek potansiyel engelinin düşmesine neden olduğu görüldü. Ayrıca, artan metal kalınlığının diyotların engel yüksekliğini ve idealite faktörünü azalttığı gözlemlendi. Bu durumun literatür (Jin et al. (1991); Yuan et al. (1993); Wang ve Ashok (1994); Jang ve Lee (2002); Chen ve Chou (2004); Forment et al. (2004)) ile iyi bir uyum sergilediği sonucuna varıldı. Ayrıca, sıcaklığa bağlı ters beslem C-V ölçümlerinden engel yüksekliği ve taşıyıcı konsantrasyonları hesaplandı. En son olarak, tüm diyotlar azot ortamında ısıl tavlama işlemine maruz bırakıldı. Burada hidrojenle önceden tavlanan diyotların genel olarak daha geç bozulduğu görüldü. Bu da üretilen diyotlarda hidrojen ile tavlama işleminin diyotun ısıl kararlılığını artırarak MESFET'lerde verimli bir şekilde kullanılabilirliğini ortaya koymaktadır. In this study, the electrical characteristics of Au/n-GaAs Schottky diodes with nm metal thickness, such as current-voltage (I-V) and capacitance-voltage (C-V), have been investigated as a function of sample temperature and thermal annealing temperature. Transport mechanisms of the diodes have been handled on the basis of single/double Gaussian barrier distribution. Also, it has been looked into impact mechanisms and effects of barrier metal thickness and hydrogen annealing procedure on the temperature dependent diode parameters. Barrier heights of the diodes fabricated from the samples annealed in hydrogen atmosphere were smaller than those of reference diodes. This was attributed to the fact that hydrogen atoms passivated dangling bonds on metal-semiconductor interface. It was seen that this result was in good agreement with studies of Jin et al. (1991); Yuan et al. (1993); Wang ve Ashok (1994); Jang ve Lee (2002); Chen ve Chou (2004); Forment et al. (2004). In addition, barrier height and carrier doping concentration of the device were obtained from temperature dependent reverse bias C-V measurements. Finally, all devices were exposed to thermal annealing in nitrogen atmosphere. It was observed that hydrogen pre-annealed devices have longer lifetimes. This demonsrates that hydrogen pre-annealing procedure enhances the stability of the diode, and can be efficiently used in MESFETs. 144

ÖZET Y. Lisans Tezi SCHOTTKY METALİNİN KALINLIĞI ve H2 TAVLAMASININ Au/rc-GaAs DİYOTLARININ KARAKTERİSTİK PARAMETRELERİ ÜZERİNE ETKİLERİ Ömer GÜLLÜ Atatürk Üniversitesi Fen Bilimleri Enstitüsü Fizik Anabilim Dalı Danışman: Yrd.Doç.Dr.Mehmet BİBER Bu çalışma, engel metal kalınlığının ve hidrojen tavlamasının metal-yarı iletken arayüzeyleri üzerinde yapacağı muhtemel etkileri incelemek için yapıldı. Bunun için, [100] doğrultusunda büyütülmüş, 450 um kalınlığında ve donor konsantrasyonu l-5xl0I7cm`3 olan «-tipi GaAs(:Te) kristali kullanıldı. Kristallerin yüzeyine buharlaştırma ile Au-Ge alaşımı kullanılarak omik kontaklar yapıldı. Daha sonra iki çeşit Schottky kontak yapıldı; birinci tip Schottky kontaklar için yarıiletken diğer yüzeyine herhangi bir işlem yapılmadan vakum ortamında farklı kalınlıklarda Au metali buharlaştırıldı. İkinci tip Schottky kontaklarda ise yarıiletkenin diğer yüzeyi metalizasyondan önce hidrojene maruz bırakıldı daha sonra vakum ortamında değişik kalınlıklarda Au metali buharlaştırıldı. Elde edilen tüm Au/«-GaAs Schottky diyotlara ait/-Fve C-V ölçümleri oda sıcaklığında ve karanlıkta yapıldı. I-V grafiklerinden engel yükseklikleri, idealite faktörleri ve ters beslem sızıntı akımları hesaplandı. Her iki tip diyot için idealite faktörü ve engel yüksekliklerinin artan metal kalınlığıyla azaldığı görüldü. Yine her iki tip diyot için elde edilen sızıntı akımlarının artan metal kalınlığıyla arttığı gözlendi. Bununla birlikte Cheung fonksiyonları kullanılarak metal kalınlığına ve hidrojen etkisine bağlı olarak idealite faktörleri, engel yükseklikleri ve seri direnç değerleri hesaplandı. Bu yöntemle hesaplanan idealite faktörleri ve engel yüksekliklerinin metal kalınlığına bağlı olarak değişiminin, /-Pden hesaplanan parametrelerin kalınlıkla değişimi ile hemen hemen benzer karakteristik sergilediği görüldü. Ters beslem C-V karakteristiklerinden elde edilen C2-V grafiklerinden engel yüksekliği, donor konsantrasyonu, difüzyon potansiyeli ve Fermi enerji seviyesi değerleri hesaplandı. Bu metot ile bulunan engel yüksekliklerinin metal kalınlığı ile değişiminin, 7-Fden elde edilen engel yüksekliğinin metal kalınlığına bağlı değişimi ile benzer karakter ortaya koyduğu bulundu. Elde edilen tüm sonuçlar literatürle karşılaştırıldı ve bulunan sonuçların literatür ile iyi bir uyum sergilediği görüldü. 2004, 84 Sayfa Anahtar Kelimeler: Schottky Diyot, Nano Kontak, Engel Metali Kalınlığı, Hidrojen Tavlaması, Termiyonik Emisyon ABSTRACT Master Thesis INFLUENCES OF THICKNESS OF SCHOTTKY METAL AND HYDROGEN ANNEALING ON THE CHARACTERISTIC DIODE PARAMETERS OF Au/H-GaAs DIODES Ömer GÜLLÜ Atatürk University, Graduate School of Naturel and Applied Sciences Department of Physics Supervisor: Asst.Prof.Dr.Mehmet BÎBER This study has been made in order to investigate the probable effect of hydogen annealing and barrier metal thickness on the metal-semiconductor interfaces. Therefore, n-GaAs(:Te) semiconductor sample with [100] orientation 450 u.m thickness and l-5xl017 cm`3 donor concentration was used. Ohmic contacts were formed by evaporation method Au-Ge alloy to the face of samples. Then two types of Schottky contacts were formed; first types of schottky contacts were made with evaporation method to the other surface of semiconductor using Au with varying metal thicknesses without a treatment in the vacuum. Whereas second types of Schottky contacts were made with evaporation method using Au with different metal thicknesses annealed in hydrogen atmosphere the other surface of semiconductor before metallisation in the vacuum. I-V and C-V measurements of all Au/«-GaAs Schottky diodes were performed at room temperature and in the dark. The barrier heights, ideality factors and reverse bias saturation currents were computed from I-V graphics. It has been seen that the ideality factors and barrier heights of both type diodes have decreased with increasing metal thickness. Nevertheless, for both type diodes it has been seen that obtained saturation currents rose with increasing metal thickness. In addition to these, ideality factors, barrier heights and series resistances by variation of metal thickness and hydrogen effect were calculated from Cheung functions. It has been seen that the variation of metal thickness of ideality factors and barrier heights obtained from Cheung functions and 7- V graphics have almost been same. The barrier heights, donor concentrations, diffusion potentials and Fermi energy levels calculated from C2-V graphics by making use of reverse bias C-V characteristics. It has been investigated that the variation of metal thickness of barrier heights obtained from C2-V graphics and I-V characteristics have exhibited similar action. All obtained results have been compared with the literature and it has been seen that evaluated results exhibited well accord with the literature. 2004, 84 Pages Keywords: Schottky diode, Nano contact, Barrier metal thickness, Hydrogen annealing, Thermionic emission 96

Günümüzde titanyum dioksit (TiO2), yapısal olarak beyaz toz halinde bulunan nano tanecikli yapısı ve ekonomik olması olağan üstü fiziksel ve kimyasal özellikleri nedeniyle en fazla araştırma yapılan metal oksit maddelerinden birisidir. Bu çalışmalarda titanyum dioksitin çok farklı kullanım alanlarına sahip olduğu görülmektedir. Gaz algılama, su arıtma, elektrokromik cihazlar, fotovoltaik hücre vb. gibi çok çeşitli uygulama alanları bulunmaktadır. Bu malzemeler, sol-jel, fiziksel buhar büyütme, kimyasal buhar büyütme ve elektrodepozisyon dahil olmak üzere farklı yöntemlerle sentezlenebilir. Bu tez çalışmasında sprey piroliz yöntemi kullanılmıştır. TiO2 ince tabakalar cam altlıklar ve inorganik yarıiletken Si (silisyum) altlık üzerine kaplanmıştır. Bu yöntem, düşük maliyetli ve kontrolü kolay bir yöntemdir. Altlıklar kimyasal temizleme işlemi yapıldıktan sonra sprey piroliz tekniği ile 25 cm yükseklikten yatay eksende 3 saniye hareketle cam altlık kaplanmıştır. Kaplama işlemi 80 ℃’de sabit sıcaklıkta tutularak yapılmıştır. Si kristali üzerine ince katmanlı tabaka oluşturulduktan sonra, üst tarafına Al metali fiziksel buharlaştırma yöntemi (PVD) ile buharlaştırıldı. Bu çalışma sonucunda TiO2 ince tabakaların yoğun ve düzgün olduğu saptanmıştır. Cam altlık üzerine oluşturulan TİO2 ince katmanlı tabakanın morfolojik yapısı ve optik özellikleri araştırıldı. Metal/TiO2/Si diyot arayüzeyleri ve elektriksel özellikleri, karanlık ortamda akım-voltaj (I-V) ve kapasitans-voltaj (C-V) ölçümleri ile araştırılmıştır., Today, titanium dioxide (TiO2) is one of the most researched metal oxide materials due to its nanoparticle structure, which is structurally in the form of white powder, and its economic and extraordinary physical and chemical properties. In these studies, it is seen that titanium dioxide has very different usage areas. Gas detection, water treatment, electrochromic devices, photovoltaic cell, etc. It has a wide variety of application areas such as These materials can be synthesized by different methods, including sol-gel, physical vapor growth, chemical vapor growth and electrodeposition. In this thesis, spray pyrolysis method was used. TiO2 thin films were coated on glass substrates and inorganic semiconductor Si (silicon) substrate. This method is low cost and easy to control. After the bases were chemically cleaned, the glass substrate was covered with the spray pyrolysis technique from a height of 25 cm in a horizontal axis for 3 seconds. The coating process was carried out at a constant temperature of 80 °C. After forming a thin layer on the Si crystal, Al metal was evaporated on the upper side by physical evaporation method (PVD). As a result of this study, it was determined that the TiO2 thin films were dense and smooth. The morphological structure and optical properties of the TIO2 thin-layer film formed on the glass substrate were investigated. Metal/TiO2/Si diode interfaces and their electrical properties were investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements in dark environment.

Teknolojik gelişmeler ve nanobilim, hem yeni bir olgunun, sanayi devrimlerinin icadının teşvik edilmesinde hem de 21. yüzyıl için ekonominin gelişmesinde önemli bir rol oynamıştır. Son zamanlarda geçiş metali oksitleri teknolojik açıdan kendine özgün özellikleri nedeniyle araştırmacıların ilgisini çekmiştir. Demir oksit ve çinko oksit nanoyapıları gibi tüm geçiş metali oksitleri arasında Magnezyum oksit (MgO) filmler, optik, optoelektronik, biyosensör, gaz algılama, kataliz, dönüştürücüler ve kapasitörler dâhil olmak üzere çeşitli bilim ve teknoloji alanlarındaki muazzam potansiyel uygulamaları nedeniyle geniş ilgi görmüştür. Metal oksitleri ilgi çekici ve ilginç yapıları, özellikleri ve değişik olgu kısımları ile son zamanlarda teknoloji ve bilim alanlarında ve uygulamalarında ilgi çeken malzemeler arasındadırlar. Birçok metal oksit akıllı camlar, gaz sensörleri, elektrokromik ve benzeri birçok alanda kullanılmaktadır. Sprey piroliz tekniği ile elde ettiğimiz Magnezyum oksit (MgO) filmlerinin özelliklerinine daha iyi çözüm bulmak amacıyla, cam veya inorganik yarıiletken (Silisyum) tabakasının üzerine büyütülmüştür. Farklı parametreler kullanılarak püskürtme tekniği ile en iyi ince film elde etmek için en uygun şartlar araştırılmıştır. Fiziksel buharlaştırma yöntemi (PVD) ile buharlaştırarak kontak oluşturmak için Silisyum yarıiletkeni üzerine ince film oluşturulduktan sonra ince filmlerin parlak yüzeyine alüminyum iletkeni ile kaplama yapılıp incelenmiştir. Karanlık ortamda incelenen bir Al/MgO/p-Si MIS Schottky diyotunun elektriksel ve arayüzey özellikleri, akım-gerilim (I-V) özellikleriyle analiz edilmiştir. Ayrıca cam üzerinde oluşturulan MgO ince filminin yapısal, yüzeysel, optiksel ve elektriksel özellikleri de sırasıyla X-Işını Kırınımı (XRD), Atomik Kuvvet Mikroskobu (AFM) ve UV-Visible Spektroskopisi yöntemleriyle incelenmiştir., Technological advances and nanoscience have played an important role both in promoting the invention of a new phenomenon, industrial revolutions, and in developing the economy for the 21st century. Recently, transition metal oxides have attracted the attention of researchers due to their unique technological properties. Among all transition metal oxides, such as iron oxide and zinc oxide nanostructures, Magnesium oxide (MgO) films have attracted wide attention due to their enormous potential applications in various fields of science and technology, including optics, optoelectronics, biosensors, gas sensing, catalysis, converters and capacitors. Metal oxides, with their intriguing and interesting structures, properties and different phenomena, are among the materials that have recently attracted attention in technology and science fields and applications. Many metal oxides are used in many fields such as smart glasses, gas sensors, electrochromics and many others. In order to find a better solution to the properties of Magnesium oxide (MgO) films obtained by spray pyrolysis technique, they were grown on glass or inorganic semiconductor (Silicon) layer. Optimal conditions were investigated to obtain the best thin film by sputtering technique using different parameters. After forming thin films on the Silicon semiconductor to form contacts by evaporation by physical evaporation method (PVD), the bright surface of the thin films was coated with aluminum conductor and examined. The electrical and interfacial properties of an Al/MgO/p-Si MIS Schottky diode were analyzed by current-voltage (I-V) characteristics. In addition, the structural, surface, optical and electrical properties of MgO thin film formed on glass were also investigated by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and UV-Visible Spectroscopy, respectively.

Bu çalışmada Orange G (OG) organik ince film kullanılarak üretilen Al/OG/p-Si diyotunun Co-60 gama ışınlamasıyla öncesinde ve sonrasında Cheung ve Norde teknikleriyle ve KEITHLEY 4200-SCS vasıtasıyla elektriksel ve arayüzey özellikleri, oda sıcaklığında, karanlık ortamda akım-gerilim(I-V) ölçümü, kapasite-gerilim (C-V) ölçümleri yapılmıştır. Yapılan ölçümler sonucundan elde edilen değerler çizelgede gösterilmiş ve grafiklendirilmiştir. Elde edilen değerler doğrultusunda bariyer yüksekliği (ɸB), idealite faktörü (n) ve seri direnç (Rs) gibi bazı parametreler Norde fonksiyonundan ve Cheung fonksiyonlarından elde edilmiştir., In this study, electrical and interfacial properties of Al/OG/p-Si diode produced by using Orange G (OG) organic thin film before and after Co-60 gamma irradiation were determined by Cheung and Norde techniques and by KEITHLEY 4200-SCS, at room temperature, in the dark environment. current-voltage (IV) measurement, capacitance-voltage (CV) measurements were made. The values obtained as a result of the measurements made are shown in the table and graphed. In line with the obtained values, some parameters such as barrier height (ɸB), ideality factor (n) and series resistance (Rs) were obtained from Norde function and Cheung functions.

Bu çalışmada katıhal devre elemanları ve malzemeler üzerindeki ışınlama etkilerinin araştırılması, pek çok bilim insanı ve farklı ülkelerin uzay ajansları konuyla ilgili çalıştıkları için ilgi çekmektedir. Bir foton veya parçacık radyasyonu katıhal devre elemanlarına ve malzemelere uygulanırsa, sert bir bozulma ortaya çıkacaktır. Bu ışınlama prosedürü aşamasında, yarıiletken aygıtlar üzerinde kalıcı veya geçici bozulma durumu oluşabilecektir. Bu tez çalışmasında, MIS diyotun fabrikasyonu için p-tipi Silisyum yarıiletken alttaşlar kullanılmıştır. Kimyasal temizlik aşamasından sonra, Al/Congo Red (CR)/p-Si MIS diyot yapısı omik arka kontak ve Al üst kontağın metalizasyonu ile üretilmiştir. Si alttaşlar üzerinde organik CR ince filmi %0.2 lik etanol çözeltisi içeren congo red çözeltisinin kaplanmasıyla yapılmıştır. Al/CR/p Si MIS kontak üzerinde ışınlama etkisini araştırmak için, Co-60 γ- ışınlamasından önce ve sonra Akım Voltaj (IV) ve Kapasite-Gerilim (CV) ölçümleri alındı. I-V verilerinden geleneksel LnI-V karakteristikleri, Cheung fonksiyonları ve Norde fonksiyonları kullanılarak, idealite faktörü (n), engel yüksekliği (Φb) ve seri direnç (Rs) hesaplandı. Ayrıca, Al/CR/p-Si MIS kontağın arayüzey durum yoğunluğu (Nss) da hasaplandı. Aygıtın C-V ölçümlerinden difüzyon potansiyeli (Vd), engel yüksekliği (Φb) ve akseptör yük konsanstrasyonu (Na) değerleri hesaplandı., The investigation of irradiation effects on solid state circuits and materials has attracted as many scientists and space agencies of the different countries are worked in the relevant topic. If the photon or particles radiation applies to the solid state circuits and materials, they will experience hard degradation. The permanent or transient degradation on the semiconductor devices may occur in this irradiation procedure. In this thesis, the p- type silicon semiconductor substrates were used for fabrication of MIS diode. After chemical cleaning procedure, Al/Congo Red (CR)/p-Si MIS diode structure was produced by metalization of ohmic back contact and Al top contact. Organic CR thin film on the Si wafers was made from covering of the congo red dye solution (0.2% in ethanol). To investigate the irradiation effect on the Al/CR/p-Si MIS contact, Current–Voltage (IV) and Capacitance-Voltage (CV) measurements were performed after and before Co-60 γ- irradiation. The ideality factor (n), the barrier height (Φb) and series resistance (Rs) from the I-V data were obtained from traditional LnI-V characteristics, Cheung functions and Norde function. Interface state density (Nss) of the Al/CR/p-Si MIS contact was also calculated. The diffussion potential (Vd), the barrier height (Φb) and acceptor charge concentration (Na) from the C-V data of the device were calculated.

Bu çalışmada; [100] doğrultusunda büyütülmüş, 300 μm kalınlıkta, donor konsantrasyonu 1-5x1017 cm-3 olan ve bir yüzü parlatılmış n-InP yarıiletkeni kullanıldı. Uygun kimyasal temizleme işleminden sonra yarıiletken kristalin alt yüzüne In omik kontak yapıldı. Üst yüzüne Safranine T boyası metanol çözeltisi (0.2’lik) ile kaplandıktan sonra organik tabakanın da üst yüzeyine alt kontak yapıldı. İmal edilen Al / ST / n-InP Schottky diyotun elektriksel ve arayüzey özellikleri, oda sıcaklığında karanlık ve ışık altında akım-gerilim (I-V) ölçümü ve 100 kHz'lik adımlarla 100-900 kHz frekans aralığında kapasite-gerilim (C-V) ve kondüktans-gerilim (G-V) özellikleri araştırılmıştır. Bariyer yüksekliği (ɸB) ve seri direnç (Rs) gibi bazı parametreler, düz beslem I-V verisi kullanılarak modifiye Norde fonksiyonundan ve Cheung fonksiyonlarından elde edilmiştir. Diyotun arayüzey durum yoğunluğu (Nss) de hesaplanmıştır. Ortaya çıkan yapı mükemmel doğrultucu özelliklere sahiptir, In this study, the [100] direction is enlarged in a thickness of 300 µm, the donor concentration 1-5x1017cm-3,and a face-polished n-InP semiconductors was used.After appropriate chemical cleaning process,the semiconductor crystal of the lower face funny In contact was made .Methanol upper face Safranine T dye solution (0.2%) is covered with the organic layer to the upper surface of the lower contact was made. Manufactured Al/ST/n-InP Schottky diodes electrical and surface properties at room temperature in the dark and the light, under the current-voltage (I-V) in the frequency range 100-900 kHz with 100 kHz steps measurement and capacitance-voltage (C-V) and conductance-voltage their properties were investigated. The barrier height (ΦB) and series resistance (Rs), some parameters such as, plain feed, the I-V data were obtained from Cheung functions and modified using the Norde function.Diode interface state density (Nss) were also calculated. The resulting structure has the characteristics of a perfect rectifier.

Bu çalışmada Batman ilinde 1 MWp'lik fotovoltaik elektrik enerjisi santrali için ölçülmüş yıllık güneş ışınımı verileri ve paket yazılım yardımıyla ön tasarımı gerçekleştirilerek sistemden elde edilecek performans değerlerinin analizi yapılmıştır. Sistem performans değerlendirmesinde PVsyst paket yazılımı tercih edilmiştir. Güneş ışınım ölçümleri anlık olarak piranometre vasıtasıyla ölçülmüştür. Sistemde öngörülen modül tercihi tekli kristal silisyum olmuştur. Güneş ışınım değerleri paket yazılıma entegre edilerek, sistem bileşenleri de seçilerek sistemden elde edilecek aylık performans değerleri karşılaştırılmıştır. Sistem analizleri aylara göre modül yerleşim düzeneği sabit eğimli ve değişken eğimli olmak üzere iki kısımda gerçekleştirilmiştir. Yapılan analizler neticesinde aylara göre modül eğiminin optimisazyonunun sistem performansını arttırdığı analizlenmiştir., In this study, prelimary desing was realized for 1 MWp photovoltaic power plant in Batman province with the help of measured sun radiation data and package software and analysis of the performance values obtained from the system was conducted. In system performance evaluation PVsyst package software was preferred. Sun radiation measurements were made instantly with the help of pyranometer. Module preference foreseen in the system was single crystal silicium. Sun radiation values were integrated into package software and system components were selected so as to compare the monthly performance values to be obtained from the system. System analyses were conducted on monthly basis in two stages (module placement setting with constant slope and with various slope). As a result of the analyses it was determined that module slope optimization on monthly basis increase the system performance.

Bu çalışmada p-tipi Silisyum kristali üzerine damlatma yöntemi kullanılarak nikel fitalosiyanin (NiPc) kaplandı. NiPc ince film üzerine termal buharlaştırma sistemi kullanılarak vakum altında saf alüminyum buharlaştırıldı ve Al/NiPc/p-Si diyotu üretildi. Al/NiPc/p-Si yarıiletken diyotun ışıksız ve ışıklı ortamda akım-voltaj (I-V) karakteristiği ölçüldü. I-V grafiği yardımıyla bu yapının doğrultucu özelliğe sahip olduğu gözlendi. Işıklı ortamdaki ölçümler 300 Watt ışık altında gerçekleştirildi ve bu ölçümler sonucunda diyotun fotodiyot özellik gösterdiği görüldü. Farklı frekanslarda kapasite-gerilim (C-V) ve kondüktans-gerilim (G-V) ölçümleri alındı. C-V ölçümleri kullanılarak bulunan C-2-V grafiklerinin eğimlerinden diyotun difüzyon potansiyeli, engel yüksekliği ve taşıyıcı konsantrasyonu değerleri hesaplandı. Ayrıca Cheung ve Norde fonksiyonları kullanılarak Al/NiPc/p-Si Schottky kontağın diyot parametreleri hesaplandı. Ayrıca kapasite-frekans (C-f) ve kondüktans-frekans (G-f) ölçümleri 0,40V-1,60V aralığında ∆V= 0,05 V adımla alındı. In this study, nickel phthalocyanine (NiPc) material has been coated onto p-type silicon by using drop cast method. Al metal was grown on the NiPc thin film by thermal evaporator system under vacuum condition and then Al/NiPc/p-Si diode was fabricated. It was performed current–voltage (I-V) measurements of Al/NiPc/p-Si semiconductor diode under dark and light illumination conditions at room temperature. It has been seen that this structure exhibits rectifying behavior from I-V plot. The I-V measurement for the illumination effect has been performed by 300watt light. It has been seen that the diode has photodiode mode. Capacitance-voltage (C-V) and conductance-voltage(G-V) measurements were performed as a function of frequency. The values of diffusion potential, barrier height and acceptor carrier density were calculated from the slope of C-2-V plot obtained by using C-V measurements. Also the diode parameters of Al/NiPc/p-Si Schottky contact were extracted by using Cheung and Norde functions. Furthermore, the measurements of capacitance-frequency (C-f) and conductance-frequency (G-f) were performed in the range of 0,40V-1,60V with a step of ∆V= 0,05 V. 75

Bu çalışmada (1 0 0) doğrultusunda büyütülmüş 1-5x10-17 cm-3 yoğunluğuna sahip p tipi InP kullanıldı. Termal buharlaştırma metodu kullanılarak bakır fitalosiyanin (CuPc) p-InP kristali üzerine kaplandı. Yine termal buharlaştırma sistemi kullanılarak oluşan ince film üzerine 5 x 10-6 torr basınç altında %99,9 saflığında alüminyum metali kaplandı ve Al/CuPc/p-InP diyotu oluşturuldu. Al/CuPc/p-InP diyotunun oda sıcaklığında, karanlık ve aydınlık ortamda akım gerilim (I-V) ölçümleri yapıldı. I-V grafiğinden bu yapının doğrultucu özellik gösterdiği görüldü. Aydınlık ortamda yapılan ölçümler 100 mW/cm2 ışık şiddeti altında yapıldı ve bu ölçümler doğrultusunda diyotumuzun fotodiyot özellik gösterdiği görüldü. Ayrıca farklı yöntemlerle Al/CuPc/p-InP Schottky diyotunun karakteristik parametreleri ( idealite faktörü (n) ,engel yüksekliği (?b) ve seri direnç (Rs) ) hesaplandı.Anahtar Kelimeler: Schottky Diyot, Bakır Fitalosiyanin, ?dealite Faktörü, Engel Yüksekliği We used p-type InP grown in the direction of (1 0 0) and has 1-5x10-17 cm-3 carrier density in this work. Copper phthalocyanine (CuPc) was covered on p-InP crystal by using thermal evaporation method. The Al/CuPc/p-InP diode was constructed by evaporating %99.9 purity aluminum metal on the thin film which composed by thermal evoparating method under presure order of 5x10-6 torr. Current-Voltage (I-V) measured was carried out for Al/CuPc/p-InP diode at room temperature, in the dark and under light. By using (I-V) graphs, it was seen that structure shows rectifying property. We use light of 100 mW/cm2 intencity and found that our diode has photodiode properties. Furthermore, Al/CuPc/p-InP Schottky diode characteristic parameters (ideality factor (n), barier height ( ?b) and series resistance (Rs) ) were calculated by different methodsKeywords: Schottky Diodes, Copper Phthalocyanine, Ideality Factor, Barrier Height 63