Yazar "Korkmaz Ş." seçeneğine göre listele
Listeleniyor 1 - 20 / 35
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The Al doping effect on the surface, optical, electrical and nanomechanical properties of the ZnO and AZO thin films prepared by RF sputtering technique(Elsevier Ltd, 2017) Pat S.; Mohammadigharehbagh R.; Özen S.; Şenay V.; Yudar H.H.; Korkmaz Ş.In this study, ZnO and aluminum doped ZnO (AZO) thin films were deposited at constant RF power of 100 W for the determine of the structural, surface, optical, electrical and nanomechanical properties. X–Ray diffraction (XRD), atomic force microscopy (AFM), nanoindentation technique and UV–Vis spectrophotometer were used. ZnO (100) and ZnO (004) orientations were detected in the ZnO and AZO films. The crystallite size values for the films were calculated as to be as 35 nm and 20 nm for ZnO and AZO thin films, respectively. It was found that the roughness values decreased to 3.15 nm from 5.15 nm for AZO and ZnO films, respectively. The hardness values of the ZnO and AZO thin films are measured as 7 GPa and 11 GPa. Young's modulus values were determined as 155 GPa and 95 GPa for ZnO and AZO films, respectively. The ZnO and AZO thin films have high transparency. © 2017 Elsevier LtdÖğe AlGaAs film growth using thermionic vacuum arc (TVA) and determination of its physical properties(Springer Verlag, 2015) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.In this research, an AlGaAs film was deposited on a microscope slide by means of the thermionic vacuum arc (TVA) technique which is a novel plasma production technique. AlGaAs structures were grown by this deposition technique for the first time and this process occurred in a very short period of time. In order to characterize the produced film, nano-structural, nano-mechanical, optical, and surface properties were determined by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray diffractometer (XRD) and interferometer. According to the results of the measurements, the mean thickness value of the produced film was obtained as 1.8 ?m. The band gap value was determined as 2eV from the Kubelka-Munk plot. The refractive index value was obtained as approximately 3.4. Hardness value was determined as 2 GPa from the Oliver-Pharr method. All these values are consistent with the reported values in the literature for the AlGaAs films produced by different methods. TVA technique appeared as a suitable and promising technique for the production of AlGaAs films. © 2015, Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg.Öğe Characterization of a fast grown GaAs:Sn thin film by thermionic vacuum arc(Springer New York LLC, 2015) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.In this research, a tin doped gallium arsenide thin film was grown on a glass substrate by means of the TVA technique in a very short period of time (70 s) and it’s morphological, compositional, and optical properties were examined. The deposited GaAs:Sn structures were characterized via both atomic force microscope (AFM) and field emission scanning electron microscope (FESEM). In this context, current research aims to reach a conclusion about the structure of the produced GaAs:Sn film by combining AFM, FESEM and energy dispersive X-ray spectroscopy data. From the optical investigation, the refractive index and extinction coefficient values for the produced film were obtained as 3.68 and 0.03 at the wavelength of 632.8 nm, respectively. The direct optical band gap energy of the deposited thin film was determined by two different models. Estimated optical band gap values were compared with each other. The results showed that TVA technique is suitable for a GaAs:Sn coating on glass substrate. © 2015, Springer Science+Business Media New York.Öğe Comparisons of surface and optical properties of the heavily carbon-doped GaN nanocrystalline films deposited by thermionic vacuum arc method(Elsevier Ltd, 2016) Pat S.; Özen S.; Şenay V.; Korkmaz Ş.In this paper, heavily C-doped GaN samples were deposited on glass and PET substrates by the thermionic vacuum arc (TVA) method, for the first time. Microstructure, surface and optical properties of the carbon-doped GaN samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy, atomic force microscopy, and UV–Vis spectrophotometer. According to XRD pattern, fullerene (C60) structures were able to deposit in doped samples, for the first time. The fullerene structures were detected at heavily carbon-doped GaN. The obtained band gap changes of heavily carbon-doped GaN samples are determined. The band gap of CGaN on PET substrate decreased to a lower value, about 100 meV. The band gaps were shifted to the lowest wavelengths towards the edge of the UV region by heavily doped carbon. (002) and (004) peaks for GaN were also detected. © 2016 Elsevier LtdÖğe Deposition of a Mo doped GaN thin film on glass substrate by thermionic vacuum arc (TVA)(Springer New York LLC, 2015) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.Current research presents a new deposition method for GaN thin films that produces in a very short production time for GaN-based solid-state applications. A Mo doped GaN thin film on a glass substrate was produced by thermionic vacuum arc (TVA) technique. The TVA technique is a novel non-reactive plasma technique. The optical properties were determined by Filmetrics F20 interferometer and UV–Vis double beam spectrophotometer. The surface morphology was analyzed using field emission scanning electron microscopy and atomic force microscopy. The mean thickness value was measured as 100 nm by Filmetrics interferometer. The crystalline structure of the produced thin film has a Wurtzite crystal structure (004) as obtained by X-ray diffraction. Hardness value was determined as 14 GPa with the Oliver–Pharr method. The obtained properties are consistent with the values reported in related literature. The findings indicate that the TVA method provides advantages for optical and industrial applications. © 2015, Springer Science+Business Media New York.Öğe Direct and fast growth of GaAs thin films on glass and polyethylene terephthalate substrates using a thermionic vacuum arc(Springer New York LLC, 2015) Pat S.; Korkmaz Ş.; Özen S.; Şenay V.Using a thermionic vacuum arc, single?crystal gallium arsenide (GaAs) layers of micron thickness were grown on PET and glass substrates in 2 min. We present a new deposition mechanism and parameters for GaAs thin films produced in a very short time. Crystal direction was found to be (111) plane for the GaAs/PET sample and (022) plane and (133) plane for the GaAs/glass sample, respectively. The average roughness values of the deposited thin films were determined to be approximately 30 nm for GaAs/PET and 60 nm for GaAs/glass. The structures can be seen clearly in field emission scanning electron microscopy and atomic force microscopy. The obtained optical band is nearly the same with literatures values of the GaAs. Although produced structures in different crystal formations, only aggregations dimensions and absorbance of the layers were changed. Obtained refractive index values are nearly same with database info. © 2015, Springer Science+Business Media New York.Öğe Effect of XRD relative intensities of the Li (002) on surface, optical and electrochemical impedance spectroscopy analyses of the deposited LiCoO2 thin film(Springer New York LLC, 2017) Yudar H.H.; Pat S.; Özen S.; Şenay V.; Korkmaz Ş.; Pat Z.In this paper, the effect of RF power on LiCoO2 thin films was investigated using X-ray diffractometer (XRD), atomic force microscopy, UV–Vis spectrophotometer, and potentiostat. The microstructural, surface, optical and electrochemical impedance measurements were performed to LiCoO2 thin films, are used to for the fully solid-state battery cathode material. According to obtained results, the relative intensities of the Li (002) crystal phase in XRD patterns of deposited LiCoO2 thin films were increased by increasing applied RF power, for the first time. The intensity of the LiCoO2 (104) plane is nearly invariant. The relative intensities of the LiCoO2 (113) plane were decreased by increasing RF power. The peak locations of the Li (002) and LiCoO2 (104) were not changed. It was found that Li (002) relative intensities affect the all investigated parameters for the LiCoO2 thin films. Especially, transmittance value increased about 20%. The band gap of the deposited film was changed 100–300 meV drastically. Deposited samples are shown high transparency in the visible region. Randles circuit was used for the equivalent circuit model. Nyquist plots, fitting parameters values and value of the circuit elements were estimated by ZSim software. © 2017, Springer Science+Business Media New York.Öğe GaN thin film deposition on glass and PET substrates by thermionic vacuum arc (TVA)(Elsevier Ltd, 2015) Pat S.; Korkmaz Ş.; Özen S.; Şenay V.In this paper, GaN thin film production was realized by thermionic vacuum arc (TVA), a plasma deposition technique, for the first time. We present a new deposition mechanism for GaN thin films with a very short production time. Microstructure properties of samples were analyzed by X-ray diffractometry. The peak at 2? = 72.88° corresponding to GaN (0004) was detected in XRD spectra. The surface morphology of the deposited GaN films was analyzed using field emission scanning electron microscopy and atomic force microscopy. The surface properties of the produced samples are quite different. The average roughness values were determined to be 0.48 nm for GaN/PET and 1.17 nm for GaN/glass. The optical properties (i.e., refractive index and reflection) were determined using an interferometer. Moreover, the obtained optical data were compared with bulk GaN materials. The refractive indexes were measured as 2.2, 3,0 and 2,5 for the GaN/glass, GaN/PET and bulk GaN, respectively. The transparencies of the different GaN-coated substrates are nearly the same. The obtained band gap values were measured in the energy range of 3.3-3.5 eV. TVA is a novel non-reactive plasma technique for the generation of metal organic thin films. The main advantage of this method is its fast deposition rate without any loss in the quality of the films. © 2015 Elsevier B.V.Öğe Heavily carbon doped GaAs nanocrystalline thin film deposited by thermionic vacuum arc method(Elsevier Ltd, 2016) Pat S.; Korkmaz Ş.; Özen S.; Şenay V.In this paper, we introduced a new different thin film deposition method for heavily carbon doped GaAs. Used method is thermionic vacuum arc (TVA) and first used for the carbon doping process. The method is very fast deposition process for the other growth method such as metal organic chemical vapor deposition, molecular beam epitaxy, molecular organic molecular beam epitaxy. The smallest grain size of GaAs and doped GaAs were obtained by carbon doping process. Mean crystalline size and height of crystalline size were found to be 3.4 nm and 4 nm, respectively. Crystal direction was found to be (022) plane and (024) plane for the sample at 45.322° and 75.060°, respectively. The production process and obtained results show that used methods is very simple, low cost, eco friendly and very fast method for the carbon doped GaAs. © 2015 Elsevier B.V.Öğe Impedance analysis of nano thickness layered AlGaN acoustic sensor deposited by thermionic vacuum arc(American Institute of Physics Inc., 2016) Özen S.; Bilgiç E.; Gülmez G.; Şenay V.; Pat S.; Korkmaz Ş.; Mohammadigharehbagh R.In this study, AlGaN acoustic sensor was deposited on aluminum metal substrate by thermionic vacuum arc (TVA) method for the first time. Gallium materials are used in many applications for optoelectronic device and semiconductor technology. Thermionic vacuum arc is the deposition technology for the variously materials and applications field. The thickness of the acoustic sensor is in deposited as nano layer. Impedance analyses were realized. Also, TVA production parameters and some properties of the deposited layers were investigated. TVA is a fast deposition technology for the gallium compounds and doped gallium compounds. Obtained results show that AlGaN materials are very promising materials. Moreover, these acoustic sensors have been produced by TVA technology. © 2016 AIP Publishing LLC.Öğe The influence of voltage applied between the electrodes on optical and morphological properties of the InGaN thin films grown by thermionic vacuum arc(John Wiley and Sons Inc., 2016) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.The aim of this research is to investigate the optical and morphological properties of the InGaN thin films deposited onto amorphous glass substrates in two separate experiments with two different voltages applied between the electrodes, i.e. 500 and 600 V by means of the thermionic vacuum arc technique. This technique is original for thin film deposition and it enables thin film production in a very short period of time. The optical and morphological properties of the films were investigated by using field emission scanning electron microscope, atomic force microscope, spectroscopic ellipsometer, reflectometer, spectrophotometer, and optical tensiometer. Optical properties were also supported by empirical relations. The deposition rates were calculated as 3 and 3.3 nm/sec for 500 and 600 V, respectively. The increase in the voltage also increased the refractive index, grain size, root mean square roughness and surface free energy. According to the results of the wetting experiments, InGaN samples were low-wettable, also known as hydrophobic. SCANNING 38:14-20, 2016. © 2015 Wiley Periodicals, Inc.Öğe Investigation of the surface free energy of the ITO thin films deposited under different working pressure(American Institute of Physics Inc., 2016) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.This study discusses the influence of working pressure on the surface energy of the ITO thin films produced by radio frequency magnetron sputtering method. Optical tensiometer (Attension Theta Lite) is used for evaluating wetting behavior of the water droplet on the film surface and Equation of State method was selected to determine surface free energy for this study. Equation of state method does not divide the surface tension into different components such as polar, dispersive, acid-base. It is calculated the surfaces' free energy measuring the contact angle with a single liquid. The surface free energy value was in the range of 15-31 mN/m. Also, the transmittances were determined in the wavelength range between 200 and 1000 nm using the UNICO 4802 UV-Vis double beam spectrophotometer. Transmittances of the produced ITO thin films are greater than %70 in the visible range. © 2016 AIP Publishing LLC.Öğe Investigation of the thickness effect to impedance analysis results AlGaN acoustic sensor(American Institute of Physics Inc., 2016) Özen S.; Bilgiç E.; Gülmez G.; Şenay V.; Pat S.; Korkmaz Ş.; Mohammadigharehbagh R.In this study, AlGaN acoustic sensors were deposited on aluminum metal substrate by thermionic vacuum arc (TVA) method, for the first time. Impedance analyses of the fabricated acoustic sensors were investigated for the determining of effect of the nano layer thickness. Thickness values are very close to each others. Fabricated sensors have been fabricated from AlGaN deposited on aluminum substrates. Gallium materials are used in many applications for optoelectronic device and semiconductor technology. Thermionic vacuum arc is the deposition technology for the variously materials and applications field. TVA production parameters and some properties of the deposited layers were investigated. TVA is the fast deposition technology for the gallium compounds and doped gallium compounds. Obtained results that AlGaN layer are very promising material for an acoustic sensor but also TVA is proper fast technology for the production. © 2016 AIP Publishing LLC.Öğe Investigation on the morphology and surface free energy of the AlGaN thin film(Elsevier Ltd, 2015) Özen S.; Şenay V.; Pat S.; Korkmaz Ş.The purpose of this paper is to analyze surface properties of AlGaN thin film produced using thermionic vacuum arc technique. Thermionic vacuum arc is an alternative deposition technique for GaN thin films that produces in a very short production time for GaN-based solid-state applications. XRD results showed that AlGaN thin film with cubic crystal structure on a amorphous glass was grown. Conductivity type of AlGaN thin film is determined as p-type by hot-probe method which is a very simple method. The surface morphology was analyzed and discussed using field emission scanning electron microscopy (FESEM) and atomic force microscopy. The contact angles in four different testing liquid and surface free energy of the AlGaN thin film were investigated by optical tensiometer. © 2015 Elsevier B.V.Öğe Investigation on the physical properties of C-doped ZnO thin films deposited by the thermionic vacuum arc(Springer Verlag, 2017) Mohammadigharehbagh R.; Özen S.; Hakan Yudar H.; Şenay V.; Pat S.; Korkmaz Ş.The aim of this study is to determine some physical properties of C-doped ZnO coated on a glass substrate by using the thermionic vacuum arc method. The produced C-doped ZnO thin film is characterized by using several analysis techniques. The produced thin film has a cubic crystal structure, high transmittance in the visible region, symmetrical surface distribution, and optical band gap energy of 3.34 eV. According to the XRD analysis of the produced thin film, it is a fullerene (C60)-doped polycrystalline ZnO. Hardness value and Young's modulus value were determined as 8 GPa and 140 GPa, respectively. These physical properties are adequate for future transparent electrode applications. © 2017, Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg.Öğe Morphology, composition, structure and optical properties of CuO/Cu2O thin films prepared by RF sputtering method(Elsevier Ltd, 2016) Korkmaz Ş.; Geçici B.; Korkmaz S.D.; Mohammadigharehbagh R.; Pat S.; Özen S.; Şenay V.; Yudar H.H.In this paper, copper oxide (CuO/Cu2O) nanocrystalline thin films were deposited by radio frequency (RF) magnetron sputtering system at 75 W and 100 W. The surface, optical, composition and structural properties of obtaining samples were characterized by using atomic force microscopy (AFM), UV–Vis spectrophotometer, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The optical band gaps of produced films were calculated as 2.05 eV and 1.83 eV for 75 W and 100 W. The layer's thicknesses were measured as 20 nm and 50 nm using a Filmetrics F20. FESEM images of the samples prove the AFM images change and also show homogeneity of thin films and variation relative to power change, thus revealed the surface of samples disturb in homogen mode. EDX results denote presence of Cu and O elements inside the deposited samples. © 2016Öğe A new method for titania thin film production: Thermionic vacuum arc method(SAGE Publications Ltd, 2017) Şenay V.; Özen S.; Pat S.; Geçici B.; Korkmaz Ş.In this research, transparent titania (TiO2) thin films were deposited on a glass microscope slide and on a flexible polyethylene terephthalate (PET) substrate under a high vacuum condition by means of the thermionic vacuum arc (TVA) method in a very short period of time (60 s). Optical properties and surface properties of the coated TiO2 surfaces are related to the structural changes of the coated layers due to ion energies and substrate effect. But obtained results are closely linked to literature values. Our analysis showed that the TVA method is an alternative method for low-temperature coatings and the produced films present important advantages for optical and industrial applications. © SAGE Publications.Öğe Optical and Surface Characteristics of Mg-Doped GaAs Nanocrystalline Thin Film Deposited by Thermionic Vacuum Arc Technique(Springer New York LLC, 2017) Pat S.; Özen S.; Şenay V.; Korkmaz Ş.Magnesium (Mg) is the most promising p-type dopant for gallium arsenide (GaAs) semiconductor technology. Mg-doped GaAs nanocrystalline thin film has been deposited at room temperature by the thermionic vacuum arc technique, a rapid deposition method for production of doped GaAs material. The microstructure and surface and optical properties of the deposited sample were investigated by x-ray diffraction analysis, scanning electron microscopy, energy-dispersive x-ray spectroscopy, atomic force microscopy, ultraviolet–visible spectrophotometry, and interferometry. The crystalline direction of the deposited sample was determined to be (220) plane and (331) plane at 44.53° and 72.30°, respectively. The Mg-doped GaAs nanocrystalline sample showed high transmittance. © 2016, The Minerals, Metals & Materials Society.Öğe Optical and surface properties of LiFePO4 thin films prepared by RF magnetron sputtering(Springer New York LLC, 2015) Volkan Ş.; Özen S.; Pat S.; Korkmaz Ş.LiFePO4 thin films with thickness values of 65 nm and 70 nm were deposited onto glass substrates by RF magnetron sputtering, using a LiFePO4 target in the argon atmosphere. A comprehensive study of the optical properties was performed and the dispersions of the constants were determined. The transmittance and absorbance spectra were measured in the wavelength range of 400-1000 nm. The films showed optical transmittance over 90% in the visible range. The optical band gap value of the films was evaluated as 3 eV. The refractive index value of the films is 1.63 at ? = 550 nm. AFM micrographs indicate smooth surface with low values ofroot mean square roughness. Contact angle measurements of several testing liquids were used to characterize each sample in terms of wettability. The films are hydrophilic as observed from contact angle measurements. The surface free energy of the film surfaces and their components (dispersive and polar) were calculated from the contact angle data using the different theories available in the literature. © 2015 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.Öğe Optical and surface properties of optically transparent Li3PO4 solid electrolyte layer for transparent solid batteries(John Wiley and Sons Inc., 2016) Pat S.; Özen S.; Şenay V.; Korkmaz Ş.In this study, optical and surface properties of the optically transparent Li3PO4 solid electrolyte layer for transparent solid battery have been investigated for the first time. To determine the optical properties, transmittance, absorbance, reflection, refractive index spectra, and optical band gap were determined by UV-Vis spectrophotometer and optical interferometer. The surface property of the transparent Li3PO4 solid electrolyte was analyzed using atomic force microscopy. One another important parameter is contact angle (CA) surface free energy (SFE). CA and SFE were determined by optical tensiometer. These values probably are a most important parameter for polymer and hybrid battery performance. For the best performance, value of CA should be low. As a result, solid electrolyte layer is a highly transparent and it has a high wettability. SCANNING 38:317–321, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.
