Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2019Scopus SJRQ2Optical, surface and magnetic properties of the Ti-doped GaN nanosheets on glass and PET substrates by thermionic vacuum arc (TVA) method
Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan
Room-temperature ferromagnetism of GaN and doped GaN materials has been reported in nanostructured form. Especially, nanoparticles show ferromagnetic properties at room temperature. In this paper, Ti-doped effects on GaN were deposited on glass and Polyethylene terephthalate (PET) substrates by thermionic vacuum arc and their room temperature magnetic properties are presented for the first time. The structure of the Ti-doped GaN was crystallized in a novel form, nano honeycomb formation. Optical and surface properties of the nano honeycombs and honeycomb nanosheets were determined. GaN and TiN phases were detected in X-ray diffraction patterns. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) device were used for imaging of the crystal structure. According to FESEM images, hexagonal crystal formations were detected for all samples. Crystal formations are very good oriented on PET substrates materials according to glass samples. The band gap value of the sample is changed by crystallization dimension. It was found that increasing crystallizations and decreasing crystal dimensions were increased the band gap of the Ti-doped GaN approximately 50 meV. Fourier transform infrared spectra and a vibrating sample magnetometer results were presented. These results confirm the Ti doped GaN honeycomb nanosheets and nano honeycombs show the room temperature ferromagnetic properties.
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İncele - MakaleYalnız künye2017Scopus SJRQ2Optical and Surface Characteristics of Mg-Doped GaAs Nanocrystalline Thin Film Deposited by Thermionic Vacuum Arc Technique
Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan
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.
AtıfScopus19WoS5OpenAlex59İncele - MakaleAçık Erişim2017Scopus SJRQ2The substrate effect on Ge doped GaN thin films coated by thermionic vacuum arc
Özen, Soner; Korkmaz, Şadan; Şenay, Volkan; Pat, Suat
This study focuses on characterization and understanding of the substrate effect on Ge doped GaN thin films coated onto transparent substrates. The produced films were deposited onto unheated glass and unheated polyethylene terephthalate by using thermionic vacuum arc technique. Gallium nitride and germanium pellets were used in the thin film production. Reflectance, refractive index and thicknesses of Ge doped GaN thin films were measured by optical interferometer using Cauchy model for fitting. The transmittances were determined in the wavelength range between 200 and 1000 nm by using UV–Vis double beam spectrophotometer. The optical Tauc method was used to determine the band gap energies of produced thin films. Surface morphologies of produced thin films were characterized by atomic force microscopy and also field emission scanning electron microscopy. In conclusion, the substrate effect on the optical and morphological properties of the produced thin films was observed.
AtıfScopus8WoS8OpenAlex9İncele - MakaleYalnız künye2017Scopus SJRQ2Investigation on the physical properties of C-doped ZnO thin films deposited by the thermionic vacuum arc
Mohammadigharehbagh, Reza; Özen, Soner; Hakan Yudar, H.; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
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.
AtıfScopus15WoS15OpenAlex16İncele - MakaleAçık Erişim2017Scopus SJRQ2Zn/ZnSe thin films deposition by RF magnetron sputtering
Yudar, H. Hakan; Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan
In this paper, Zn/ZnSe thin films were deposited on glass substrates by RF magnetron sputtering system. XRD analyses were done. Zn and ZnSe phases were obtained. Miller indices of obtained Zn phases were detected in (320), (620) and (112) crystal formation. For the ZnSe phases, only one peak of (110)/(220) was observed. The surface morphology of the samples was investigated by an atomic force microscopy tools. It found that average roughness of the films was increased by raised RF power. The thin films around 80 % of high transmittance were measured. The band gap values were calculated as to be ~2.80 eV by the Cauchy model. The calculated refractive indices values were approximately 2.25 by a relation between the refractive index and the band gap.
AtıfScopus31WoS24OpenAlex29İncele - MakaleAçık Erişim2017Scopus SJRQ2A new method for titania thin film production: Thermionic vacuum arc method
Şenay, Volkan; Özen, Soner; Pat, Suat; Geçici, Birol; Korkmaz, Şadan
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.
AtıfScopus7WoS6OpenAlex7İncele - MakaleAçık Erişim2017Scopus SJRQ2Effect of XRD relative intensities of the Li (002) on surface, optical and electrochemical impedance spectroscopy analyses of the deposited LiCoO2 thin film
Yudar, H. Hakan; Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan; Pat, Zerrin
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.
AtıfScopus4WoS3OpenAlex4İncele - MakaleYalnız künye2017Scopus SJRQ1A study on some physical properties of a Pb-doped GaAs thin film produced by thermionic vacuum arc
Şenay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Şadan
A 155 nm Pb-doped GaAs thin film was deposited on a glass substrate by means of the thermionic vacuum arc technique in 30 s using GaAs and Pb pellets as source materials. Tools and techniques such as an optical reflectometer, UV-VIS-NIR spectrophotometer, FESEM, EDX, AFM and optical tensiometer were employed to investigate the physical properties of the produced film. From the optical investigations, the refractive index at the wavelength of 632.8 nm and optical band gap of the film were found to be 4.03 and 1.13 eV respectively. It was observed that Pb doping increased the value of refractive index and decreased the band gap value. A uniform surface morphology with fine grain covering the entire surface was observed through the FESEM and AFM studies while 50–80 nm grain size and 2.22 nm root mean square roughness values were obtained. The EDX analysis confirmed the presence of Ga, As and Pb elements in the film. The wetting experiments revealed that the contact angle value was dependent on the liquid used. The surface free energy calculated with OWRK/Fowkes and Equation of State approaches were about 26 mN/m.
AtıfScopus6WoS6OpenAlex5İncele - MakaleYalnız künye2017Scopus SJRQ2The surface morphology research of the BGaN thin films deposited by thermionic vacuum arc
Özen, Soner; Pat, Suat; Şenay, Volkan; Korkmaz, Şadan
In this paper, BGaN thin films with two different thicknesses were deposited on two different substrates and their surface morphologies were investigated. The amorphous glass and semi-crystalline polyethylene terephthalate substrates were selected. At the same time, two different deposition angles are selected with a view to the effect of deposition angle on surface morphology. The surface and optical properties were determined by using X-ray diffractometer (XRD), atomic force microscope (AFM), spectroscopic ellipsometry (SE) and optical interferometer. The thicknesses of thin films on substrates are about 30 nm and 40 nm. According to the atomic force microscope images, small-dimensional grains observed on relatively large grains. The roughness values of the thin films on the polyethylene terephthalate substrate are lower than on the glass substrate.
AtıfScopus10WoS9OpenAlex10İncele - MakaleYalnız künye2017Scopus SJRQ2The Al doping effect on the surface, optical, electrical and nanomechanical properties of the ZnO and AZO thin films prepared by RF sputtering technique
Pat, Suat; Mohammadigharehbagh, Reza; Özen, Soner; Şenay, Volkan; Yudar, H. Hakan; Korkmaz, Şadan
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.
AtıfScopus50WoS50OpenAlex57İncele - MakaleAçık Erişim2016Scopus SJRQ2Surface, Nanomechanical, and Optical Properties of Mo-Doped GeGaAs Thin Film Deposited by Thermionic Vacuum Arc
Pat, Suat; Senay, Volkan; Özen, Soner; Korkmaz, Sadan
Mo-doped and undoped GeGaAs layers have been deposited by the thermionic vacuum arc (TVA) method, an alternative, fast plasma deposition technique. The thicknesses of the deposited layers were identical. The surface, mechanical, and optical properties of the deposited layers were studied to determine the influence of Mo doping on GeGaAs. The transparency of GeGaAs was shifted towards the near-infrared region by Mo doping. Bandgap values shifted by approximately 0.3 eV. In other words, the bandgap value of Mo-doped GeGaAs was nearly equal to that of GaAs materials. The average roughness and grain size of the Mo-doped material were smaller than for the GeGaAs layer. The particle distributions of the Mo-doped and undoped GeGaAs were almost perfect Gaussians. However, the mean height of the Mo-doped GeGaAs grains was six times that for undoped GeGaAs. The surface was homogeneous. The Mo-doped layer showed greater absorbance than the GeGaAs material. The produced Mo-doped sample showed hybrid properties.
AtıfWoS1OpenAlex1İncele - MakaleYalnız künye2016The Effects of Boron Alloying on the Structural and Optical Properties of GaAs Deposited by a Thermionic Vacuum Arc Method
Pat, Suat; Korkmaz, Sadan; Özen, Soner; Senay, Volkan
This study reports the influence of the boron alloying on the structural and optical properties of GaAs compound for the first time. UV-Vis-NIR spectrophotometer, interferometer, photoluminescence spectrophotometer, X-ray diffraction, field emission scanning electron microscopy, and atomic force microscopy tools were used for the determination of the structural and optical properties. As results, boron atoms affect the bang gap to upper energy level with very small variations. But, structural properties and grain dimensions of GaAs have improved by adding boron atoms. The results show that used method, thermionic vacuum arc, is the fast, direct, environmental and very easy-doped BGaAs ternary compounds deposition method according to other methods. Finally, this method is a promising method for GaAs technology.
AtıfWoS2OpenAlex4İncele - MakaleYalnız künye2016Scopus SJRQ1Optical, structural, morphological and compositional characterization of a Co-doped GaAs semiconducting thin film produced by thermionic vacuum arc
Şenay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Şadan
A 80 nm 2 at% Co-doped GaAs thin film was deposited on a glass substrate under a high vacuum condition by means of the thermionic vacuum arc technique using GaAs and Co pellets as source materials. Tools and techniques such as an optical reflectometer, XRD, UV-VIS-NIR spectrophotometer, FESEM, EDX, and AFM were employed to investigate some of the physical properties of the produced film. From the optical investigations, the refractive index at 632.8 nm and optical band gap of the film were determined to be 3.60 and 1.42 eV respectively. XRD characterization indicated that the film contained GaAs and Co phases. A uniform surface morphology with fine grain covering the entire surface was observed through the FESEM and AFM studies, while 30 nm grain size and 2.72 nm root mean square roughness were obtained. The EDX analysis also confirmed the presence of Ga, As and Co in the film.
AtıfScopus19WoS17OpenAlex18İncele - MakaleYalnız künye2016Scopus SJRQ2Optical and surface properties of optically transparent Li3PO4 solid electrolyte layer for transparent solid batteries
Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan
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.
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İncele - BildiriYalnız künye2016Some physical properties of Co-doped GaAs thin films grown by thermionic vacuum arc
Şenay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Şadan; Mohammadigharehbagh, Reza; Akkus, B.; Dogan, G.S.; Mutlu, R.B.C.; Yalcin, L.S.; Oktem, Y.
Cobalt doped GaAs thin films with the thickness of 100 nm and 200 nm were deposited on glass substrates by a thermionic vacuum arc system. The optical and surface properties were investigated as functions of the film thickness. The refractive index of the films decreased with the increasing thickness. A band gap value of 1.42 eV was obtained for the 100 nm film and 1.38 eV for the 200 nm film from the Tauc plots of (αhν)2 vs. hν. According to the results obtained from the AFM studies, the root mean square surface roughness of the films were nm and 3.13 nm for the 100 nm and 200 nm film, respectively.
AtıfScopus1WoS1OpenAlex1İncele - BildiriYalnız künye2016Investigation of the surface free energy of the ITO thin films deposited under different working pressure
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Akkus, B.; Dogan, G.S.; Mutlu, R.B.C.; Yalcin, L.S.; Oktem, Y.
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.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2016Scopus SJRQ2Morphological and optical comparison of the Si doped GaN thin film deposited onto the transparent substrates
Ozen, Soner; Senay, Volkan; Pat, Suat; Korkmaz, Sadan
The aim of this paper is to expand the body of knowledge about the silicon doped gallium nitride thin films deposited on different substrates. The physical properties of the Si doped GaN thin films deposited on the glass and polyethylene terephthalate substrates by thermionic vacuum arc which is plasma production technique were investigated. Thermionic vacuum arc method is a method of producing pure material plasma. The Si doped GaN thin films were analyzed using the following methods and the devices: atomic force microscopy, X-ray diffraction device, spectroscopic ellipsometer and energy dispersive X-ray spectroscopy detector. The produced Si doped GaN thin films are in the (113) orientation. The thicknesses and refractive index were determined by using Cauchy dispersion model. Surface morphologies of produced thin films are homogenous and low roughness. Our analysis showed that the thermionic vacuum arc method present important advantages for optical and industrial applications.
AtıfScopus8WoS7OpenAlex10İncele - MakaleYalnız künye2016Scopus SJRQ2Comparisons of surface and optical properties of the heavily carbon-doped GaN nanocrystalline films deposited by thermionic vacuum arc method
Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan
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.
AtıfScopus6WoS5OpenAlex7İncele - MakaleAçık Erişim2016Scopus SJRQ2Optical and surface properties of the in doped GaAs layer deposition using thermionic vacuum arc method
Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan; Şimşek, Veli
A broadband optical transparent InGaAs semiconductor layer production of micron thicknesses was produced in only 75 s by thermionic vacuum arc (TVA) method at the first time. The optical and surface properties of the produced layers have been investigated. InGaAs structure is using in electronics and optoelectronics devices. The main advantage of TVA method is its fast deposition rate, without any loss in the quality of the films. Doping is a very simple and fast according to common production methods. InGaAs is an alloy of indium arsenide (InAs) and gallium arsenide (GaAs). InAs with (220) crystallographic direction and GaAs with (024)/(022) crystallographic directions were detected using by XRD analysis. GaAs and InAs are in the cubic and zinc blende crystal system, respectively. According to the transmittance spectra, sample has a broadband transparency in the range of 1000–3300 nm. According to results, defined TVA method for In doping to GaAs is proper fast and friendly method. SCANNING 38:297–302, 2016.
AtıfScopus1WoS1OpenAlex3İncele - Derleme MakaleYalnız künye2016Scopus SJRQ4Influence of oxygen partial pressure on the metastable copper oxide thin films
Geçici, Birol; Korkmaz, Šadan; Özen, Soner; Šenay, Volkan; Pat, Suat
Paramelaconite (Cu4O3) is a metastable copper oxide. Metastable copper oxide thin films were deposited on glass substrates by reactive RF magnetron sputtering in argon (Ar) and oxygen (O2) gas mixture atmospheres. Ar/O2 gas ratios in the sputtering ambient were chosen as 1/1 and 1/9. The surface and optical properties were determined by X-ray diffractometer (XRD), atomic force microscope (AFM) and UV-Vis spectrophotometer. The XRD patterns of the samples exhibited single strong diffraction peaks at 35.39° and 35.49° , corresponding to the (202) peak of Cu4O3. The mean thickness values were measured as 100 nm and 80 nm for the films deposited at 1/1 and 1/9 Ar/O2 gas ratios, respectively. The samples showed low transmittance and high absorbance in the high frequency region.
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