Sürdürülebilir Kalkınma Amaçları

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  • MakaleAçık Erişim2025Scopus SJRQ3
    Tailoring the optoelectronic properties of ZnO nanowires via TiO2 coating

    Sarac, Mehmet Fahri; Mert, Merve; Solakyildirim, Tuba; Teber, Ahmet

    The photosensing properties of TiO2/ZnO nanowires (NWs) were investigated by sequential deposition using thermal oxidation and sol–gel. It was found that TiO2/ZnO NWs with 5 mM concentration exhibit a higher aspect ratio compared to the 10 mM and 25 mM TiO2/ZnO NWs. The surface-to-volume ratio directly influences the photoluminescence (PL) intensity and electrical properties of the ZnO NWs. XPS confirmed the presence of TiO2 on the surface, while EDS detected titanium, with its concentration increasing as the TiO2 concentration rises. The photosensing performance of ZnO has been significantly improved by modifying it with TiO2. However, determining the optimum concentration is a critical factor in performance improvement. The findings show that high TiO2 concentrations improve surface properties, but excessive coating may limit carrier mobility. Photosensitivity has been increased at lower TiO2 concentration due to a higher surface-to-volume ratio (SVR) and, as a result, higher surface photoactivity. The 25 mM TiO2/ZnO NW array stands out in optimal detectability and photoresponsivity due to the reduced resistance caused by the increased Ti concentration on the surface. The 25 mM TiO2/ZnO NWs achieved the highest photoresponsivity (717 mA/W) and specific detectivity (1.48 × 101° Jones), while the 5 mM TiO2/ZnO NWs exhibited exceptional photosensitivity (320.11%), making them ideal for UV detection. The samples at varying concentrations show promise in photosensitivity, detectability, and photoresponsivity, making them suitable for environmental sensors, UV detectors, and other optoelectronic applications.

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  • MakaleAçık Erişim2020Scopus SJRQ2
    Optical, morphological and nano-mechanical properties of chromium oxide thin films fabricated by radio frequency (RF) magnetron sputtering

    Özen, Soner; Şenay, Volkan

    In this research, two transparent chromium oxide thin films having different thickness values were simultaneously deposited on glass substrates by adjusting target-substrate distance by means of radio frequency (RF) magnetron sputtering technique. The effect of film thickness on optical, morphological and nano-mechanical properties of the produced thin films were analyzed by using UV-VIS spectrophotometer, interferometer, tensiometer and atomic force microscope. The transmittance and absorbance of the films were measured in the incident photon wavelength range of 300–1000 nm. The optical energy band gap value of the produced thin films was estimated to be approximately 4 eV from the obtained absorbance data via Tauc's method. According to the results obtained from nano-mechanical tests, the produced thin films were highly scratch resistant. From the wetting experiments, it was found that the surfaces of the films were hydrophilic.

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  • MakaleYalnız künye2020Scopus SJRQ1
    Thin films derived from Zn(Al)O mixed metal oxides nanoparticles dispersed in polyethylene glycol: Structural, morphological and optical properties

    El Hassani, Kaoutar; Bayram, Ozkan; Anouar, Abdellah; Mavi, Ahmet

    In this study, Zn(Al)O thin films were produced using colloidal solution of Zn(Al)O nanoparticles dispersed in polyethylene glycol (PEG). Zn(Al)O mixed metal oxides were obtained by a simple pyrolysis of Zn–Al containing layered double hydroxide materials with different Al content. Survey of textural analysis of Zn(Al)O mixed oxides displayed characteristic peaks of ZnO structure. The calculated ratios of lattice parameters c/a were found to be 1.61 and 1.60 for 3-ZAO and 5-ZAO, respectively. The optical transmittance of the prepared thin films was not significantly affected by the increase in Al content; however, this increase changed the optical band gap from 3.27 eV to 3.33 eV. ZAO thin films, which are both cost-effective with good optical properties, have the potential to be an alternative to those used in many optical devices lately.

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  • MakaleAçık Erişim2019Scopus SJRQ2
    Optical and surface properties of ZnN thin films manufactured by radio frequency reactive magnetron sputtering

    Şenay, Volkan; Özen, Soner; Aydoğmuş, Tuna

    ZnN is a relatively new material and its physical properties are not yet well studied. In this research, ZnN thin films having different thickness values were deposited on glass substrates by means of radio frequency (RF) reactive magnetron sputtering technique at room temperature and some physical properties of ZnN thin films were investigated by several techniques. UV–vis spectrophotometer and reflectometer were employed to investigate the optical properties of the produced thin films. The surface properties were investigated by using tensiometer and atomic force microscope (AFM). The effects of film thickness on the optical and surface properties of ZnN thin films were discussed. The refractive index and band gap values were found to be dependent on thickness of ZnN thin films. The AFM investigations indicated that the surfaces of the films are compact and smooth. From the wetting experiments, it was found that the surfaces of the films are hydrophobic and surface free energy values are low as reported in literature.

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  • MakaleAçık Erişim2019Scopus SJRQ2
    Optical, 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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  • MakaleYalnız künye2017Scopus SJRQ2
    Optical 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.

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  • MakaleAçık Erişim2017Scopus SJRQ2
    A 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.

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  • MakaleYalnız künye2017Scopus SJRQ2
    The 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.

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  • MakaleYalnız künye2016
    The 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.

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  • MakaleYalnız künye2016Scopus SJRQ2
    Optical 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.

    • SDG 7 · Erişilebilir ve Temiz Enerji
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  • BildiriYalnız künye2016
    Some 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.

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  • MakaleYalnız künye2016Scopus SJRQ2
    Morphological 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.

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  • MakaleYalnız künye2016Scopus SJRQ2
    Comparisons 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.

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  • MakaleAçık Erişim2016Scopus SJRQ2
    Optical 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.

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  • MakaleYayıncıda açık erişim2016Scopus SJRQ2
    The influence of voltage applied between the electrodes on optical and morphological properties of the InGaN thin films grown by thermionic vacuum arc

    Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan

    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.

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  • MakaleAçık Erişim2016Scopus SJRQ1
    Heavily carbon doped GaAs nanocrystalline thin film deposited by thermionic vacuum arc method

    Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan

    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.

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  • MakaleYalnız künye2016Scopus SJRQ2
    Morphology, composition, structure and optical properties of CuO/Cu2O thin films prepared by RF sputtering method

    Korkmaz, Şadan; Geçici, Birol; Korkmaz, S. Deniz; Mohammadigharehbagh, Reza; Pat, Suat; Özen, Soner; Şenay, Volkan; Yudar, Hafizittin Hakan

    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.

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  • MakaleAçık Erişim2015
    Optical, Structural and Morphological Characterization of a Zn-Doped GaAs Semiconducting Thin Film Produced by Thermionic Vacuum Arc

    Senay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Sadan

    A 780 nm thick Zn-doped GaAs p-type semiconducting film was deposited onto a glass substrate under a high vacuum condition by means of the thermionic vacuum arc technique in a very short period of time (90 sec) using GaAs and Zn pellets as source materials. In order to characterize the produced film, the optical constants and absorbance of the film were measured using optical methods. By using the obtained optical absorbance data, the optical band gap was estimated from the Tauc plot based on the relation (alpha hv)(2) = B(hv - E-g). The refractive index value of the film was 3.73 at lambda = 632.8 nm. The band gap was estimated to be 1.35 eV. According to the results obtained from the FESEM and AFM related studies, the produced film displayed a granular surface morphology with a root mean square roughness of 17 nm. Contact angle measurements of several testing liquids were used to characterize the film in terms of wettability. It was found that the contact angle value was dependent on the liquid used. However, the film was hydrophilic as observed in contact angle measurements.

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  • MakaleYalnız künye2015Scopus SJRQ3
    A study on optical, morphological and mechanical properties of Al2O3 ultra-thin films deposited by RF reactive magnetron sputtering

    Pat, Suat; Özen, Soner; Şenay, Volkan; Aydoʇmuş, Tuna; Elmas, Saliha; Korkmaz, Şadan; Ekem, Naci; Balbaʇ, M. Zafer

    The Al2O3 ultra-thin films with the thicknesses of 30 nm and 35 nm were deposited on glass microscope slides by a radio frequency reactive magnetron sputtering system. The optical, morphological and mechanical properties were investigated as function of the film thickness. The refractive index of the resulting Al2O3 ultra-thin film increased with the increasing thickness. Both the films showed high transparency of > 85% and low reflectivity of < 10% in the visible and near infrared region. A band gap of ∼8.65 eV was obtained for the 30 nm film and ∼7.53 eV for the 35 nm film from an empirical relation between refractive index and band gap. According to the results obtained from the AFM studies, the root mean square surface roughness of the films are 3.67 nm and 3.77 nm for the 30 nm and 35 nm film, respectively. The hardness and Young modulus values decreased with the increasing film thickness.

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  • MakaleYalnız künye2015Scopus SJRQ2
    GaN thin film deposition on glass and PET substrates by thermionic vacuum arc (TVA)

    Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan

    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 2θ = 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.

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