Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2021Scopus SJRQ2Photoluminescence and structural properties of zirconium dioxide thin films produced by RF sputtering technique
Bakacak, Pinar K.; Gur, Emre; Bayram, Ozkan; Tuzemen, Sebahattin; Simsek, Onder
In this study, Zirconium Oxide (ZrO2) thin films were produced by using radio frequency magnetron sputtering method on glass substrate at various pressures. The effects of growth pressure on the characteristics of grown Zirconia nanostructures were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Uv-Visible Spectroscopy and Photoluminescence Spectrometry (PL). XRD analysis showed that peaks of the monoclinic and tetragonal phases were more effective at low growth pressure, but different monoclinic phase peaks were present at increasing growth pressures. The surface morphological properties of the films such as average and maximum roughness, changed significantly with increasing growth pressure, and the maximum peak height first increased to 40 nm and then decreased to 20 nm. The optical transmittance of these thin films was examined in the 450–1100 nm wavelength range, covering both the visible and near-infrared spectral range, and it was found to be approximately 95% at 550 nm wavelength, and the optical band gaps were calculated to be approximately 3.26 eV by PL analyses. Uv-Visible spectroscopy analysis showed that the refractive index of the Zirconia films decreases from 2.09 to 1.79 with increasing wavelength of the incident photon. ZrO2 thin films are considered potential materials for transparent electronic devices because of their high transmittance value.
AtıfScopus5WoS4OpenAlex5
İncele - MakaleAçık Erişim2021Scopus SJRQ13D-graphene-laser patterned p-type silicon Schottky diode
Orhan, Elif Oz; Efil, Esra; Bayram, Ozkan; Kaymak, Nuriye; Berberoğlu, Halil; Candemir, Ozun; Pavlov, Ihor; Ocak, Sema Bilge
The influence of the laser patterning (LP) process on the quality of graphene (Gr) film and Schottky diode characteristics was researched in this study. First of all, p-type silicon (Si) was patterned by homemade femtosecond laser source. To compare the resulting effect, non-patterned n-Si and p-Si were used as substrates. To achieve vertically oriented three-dimensional (3D) Gr nanosheets (VGNs) onto the laser patterned p-type Si, non-patterned n-Si, and p-Si substrates, we used Radio-Frequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) technique. Then, Raman analyses for VGNs obtained on patterned and non-patterned p-Si and n-Si substrates were conducted. All results indicate that the Gr obtained on all substrates is vertically oriented. Scanning electron microscopy (SEM) analyses were also performed to obtain information about the morphological properties of the 3D Gr structure. In addition, the influence of the laser patterning at the Gr-Si interface was evaluated by comparing two sets of devices which are junctions of Gr-Laser Patterned Si (Gr-LPSi) and Gr-Insulator-Silicon (Gr-I-Si) at 300 K in the dark medium. D1 device consists of a Gr-LPSi junction that involves RF-PECVD grown Gr on the silicon, whose surface exposed the laser beam for patterning. D2 device consists of a Gr-I-Si junction that involves RF-PECVD grown Gr onto the silicon, whose surface involves a thin native oxide layer (~2 nm). The results show that the laser treatment causes an increment in Schottky barrier height (SBH) and decreases leakage currents under a reverse bias voltage of the diode. Notably, we have seen the influence of the laser patterning process on 3D Gr nano-sheets which is that the entire surface of the substrate has now reformed new structures in the nano-sphere and nano-rose morphology, so we believe that this is the first work that shows these structures in this form.
AtıfScopus14WoS13OpenAlex13İncele - MakaleAçık Erişim2021Scopus SJRQ2Dielectric characteristics and electrical conductivity behavior of graphene/Al2O3/p-type silicon structure
Kaymak, Nuriye; Oz Orhan, Elif; Bayram, Ozkan; Bilge Ocak, Sema
Graphene nanosheets (Gns) obtained by the chemical vapor deposition (CVD) method have been employed for the fabrication of Graphene/Al2O3/p-type silicon (Si) structure. The Raman, scanning-electron-microscopy (SEM) and transmission-electron-microscopy (TEM) have been used to analyze the morphology and structural features of the graphene nanosheet. The dielectric features and electrical-conductivity of Graphene/Al2O3/p-type Si have been studied in the frequency range 10 kHz–400 kHz and in the voltage range, −4 V to +4 V at 300 K. The obtained experimental outcomes imply that electrical conductivity and dielectric features of Graphene/Al2O3/p-type Si were found out to be powerful functions of frequency and applied bias voltage. It can be seen that almost all of the interface states between metal and silicon contribute to modify of dielectric features of Graphene/Al2O3/p-type Si structure.
AtıfScopus6WoS6OpenAlex6İncele - MakaleAçık Erişim2021Scopus SJRQ1Photovoltaic performance of non-covalent functionalized single-layer graphene in dye-sensitized solar cells (DSSCs)
Igman, Erdal; Bayram, Ozkan; Mavi, Ahmet; Hasar, Ugur Cem; Simsek, Onder
In this study, it was aimed to fabricate new effective alternative counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). For this purpose, firstly, single-layer graphene (SLG) thin films were grown by chemical vapor deposition (CVD) method. Then, these films were separately functionalized with 1,8-cineole (ppCin/SLG), D-Limonene (ppLim/SLG) and Thiophene (ppTh/SLG) by plasma polymerization. Number of layers in CVD-grown graphene determined by Raman, transmission electron microscope (TEM) and ultraviolet–visible (UV–Vis) spectroscopy. Chemical structures of plasma polymerised (pp) thin films were investigated by Fourier transform infrared (FTIR) spectroscopy. Photovoltaic parameters of DSSCs were calculated, and electrocatalytic properties of CEs were investigated by electrochemical impedance spectroscopy (EIS). Polymer functionalization greatly enhanced the electrical conductivity and electrocatalytic activity properties of graphene compared to that of SLG. The efficiencies of DSSCs with ppCin/SLG and ppLim/SLG CEs were 1.10% and 1.02%, respectively. As a result, the cell efficiencies of ppCin/SLG and ppLim/SLG could be as alternative materials to platinum (Pt) counter electrode.
AtıfScopus14WoS13OpenAlex14İncele - MakaleYalnız künye2021Scopus SJRQ2Double-exponential current-voltage (I-V) behavior of bilayer graphene-based Schottky diode
Kutluoǧlu, Esra Efil; Orhan, Elif Oz; Tataroǧlu, Adem; Bayram, Ozkan
Researches on layered materials such as graphene have attracted lots of attention recently. It has been shown that these materials have make a junction with many semiconductor materials that behave like Schottky diodes and have rectifying characteristics. The comprehension of its fabrication process and properties are a critical need toward graphene-based integrated electronics. The purpose of this study is to find out the current-voltage (I-V) performance of Bilayer Graphene (BLGr) based heterostructure fabricated on Al2O3/p-Si, and the effect of BLGr on diode parameters. Graphene has been grown on copper (Cu) foil by Chemical Vapor Deposition (CVD) method and transferred onto Al2O3/p-Si by using the polymethyl methacrylate (PMMA) wet transfer method. Raman analysis has been performed to obtain supportive information about CVD synthesized graphene film. The I-V plot of the diode exhibited two linear regions named Region 1 (0.08-0.19 V) and Region 2 (0.21-0.40 V). The double-exponential I-V behavior of the diode has been analyzed. The diode characteristics such as barrier height (ΦB0), series resistance (Rs), and ideality factor (n) have been calculated by using thermionic emission (TE), Norde, and Cheung methods. Especially, the values of the barrier height were compared with one another. It was found that they are in good agreement. Additionally, current conduction mechanisms of the diode were investigated using the forward bias ln(I) versus ln (V) plot. At lower and higher forward bias regions, the conduction mechanisms were determined as ohmic behavior and trap charge limiting current mechanism (TCLC), respectively.
AtıfScopus3WoS3OpenAlex4İncele - MakaleYalnız künye2020Scopus SJRQ2Electrical properties of Graphene/Silicon structure with Al2O3 interlayer
Kaymak, Nuriye; Bayram, Ozkan; Tataroğlu, Adem; Bilge Ocak, Sema; Oz Orhan, Elif
The electrical properties of the fabricated Al/Gr/Al2O3/p-Si structure have been analyzed using frequency-dependent capacitance/conductance–voltage (C/G–V) measurements. Graphene (Gr) nanosheets were grown on to copper (Cu) catalyst substrate, which has 99.99% purity, by Chemical Vapor Deposition (CVD) technique, and then the Graphene was transferred on Al2O3/p-Si by the standard transfer process. The Graphene structures have been characterized by Raman Spectroscopy and Transmission Electron Microscopy (TEM) analyses, and the results of both analyses confirmed the monolayer/bilayer Graphene nanostructure. The forward and reverse bias G–V and C–V measurements of this structure have been performed in 10 kHz–400 kHz and at 300 K. The frequency dispersion in C and G can be evaluated for interface state density (Dit) and series resistance (Rs) values. The values of Dit and Rs are dependent on frequency and increase with decreasing frequency. The Rs- V graph shows a peak form at all frequencies in the depletion region and vanishes with increasing frequency. The obtained results suggest that the prepared structure can be used in electronic device applications.
AtıfScopus25WoS23OpenAlex23İncele - MakaleYalnız künye2020Scopus SJRQ1Current–voltage analyses of Graphene-based structure onto Al2O3/p-Si using various methods
Efil, Esra; Kaymak, Nuriye; Seven, Elanur; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge; Tataroglu, Adem
The present study's main purpose is to determine the current-voltage (I–V) performance of Graphene (Gr) based hetero nanostructure produced on Al2O3/p-Si. Graphene synthesis was carried out using the chemical vapor deposition (CVD) technique on Copper (Cu) foils used as a metal catalyst and transferred onto Al2O3/p-Si using the conventional transfer method. The I–V characteristics of this structure were measured in the dark environment, and the electrical properties of the Gr/Si structure were characterized at room temperature. The rectifying ratio (RR) of the structure was found to be about 103 at ± 3 V. The electrical properties of ideality factor (n), series resistance (Rs), and barrier height (Φb) were examined by using the theory of Thermionic Emission (TE), Norde's method, and Cheung's method. The values of Φb, which were calculated using Norde's method, Cheung's method, and the theory of thermionic emission (TE), were found to be 0.69 eV, 0.71 eV, and 0.68 eV, respectively. The ideality factor was found to be approximately 3.89 according to the theory of TE. The values of series resistance were also determined using the Norde's method and Cheung's two different parameters (dV/dln(I) and H(I)) found to be 9.60 kΩ, 9.12 kΩ, and 5.94 kΩ, respectively.
AtıfScopus25WoS25OpenAlex26İncele - MakaleAçık Erişim2020Scopus SJRQ2Graphene/polyaniline nanocomposite as platinum-free counter electrode material for dye-sensitized solar cell: its fabrication and photovoltaic performance
Bayram, Ozkan; Igman, Erdal; Guney, Harun; Demir, Zeynep; Yurtcan, Mustafa Tolga; Cirak, Cagri; Hasar, Ugur Cem; Simsek, Onder
In this study, it was aimed to produce graphene/polyaniline nanocomposite thin films as counter electrode materials by PECVD system and to determine the photovoltaic performances of these counter electrodes in dye-sensitized solar cells (DSSCs). Graphene/polyaniline counter electrode (GPCE) material was produced in two different steps. Firstly, a single-layer and multilayer graphene thin films were produced on the fluorine-doped tinoxide (FTO) substrates. Then, polyaniline (PANI) thin films were grown on each graphene thin films using plasma polymerization technique, and eventually the production of the graphene/PANI nanocomposite was completed. The fabricated graphene/PANI nanocomposites were used in place of platinum (Pt)-counter electrode which is widely used in DSSCs and the photovoltaic performance of these counter electrodes was investigated. The DSSCs consisted of titanium dioxide (TiO2) nanotube photoanode, N719 dye, iodolyte liquid electrolyte, and graphene/PANI nanocomposite counter electrode. I–V measurements were carried out in order to calculated photoconversion efficiency (PCE) and it was found that the these efficiency of GPCEs changed between 0.56 and 1.36% according to the number of graphene layers. The photovoltaic performance of DSSC, consisting of TiO2 nanotube photoanode and Pt-counter electrode was 1.1%.
AtıfScopus33WoS25OpenAlex29İncele - MakaleYalnız künye2020Scopus SJRQ1Thin 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.
AtıfScopus4WoS3OpenAlex4İncele - MakaleAçık Erişim2019Determination of the Optical Properties of ppTh Nanostructured Films Obtained by RF Plasma Polymerisation Technique
Bayram, Ozkan
In this study, it is aimed to obtain plasma polymerized Thiophene (ppTh) thin films by Radio Frequency (RF) plasma polymerization technique and to determine optical, chemical and morphological properties of these films. ppTh thin films were fabricated at 25, 50, 75 and 100 W RF power, 15 minutes coating duration and 500 mTorr base pressure. ppTh thin films were analyzed by Scanning Electron Microscopy (SEM), FTIR and Uv-Vis spectroscopy. Functional groups of thin films were determined by FTIR spectroscopy, and it was investigated how coating parameters affect the chemical structure of these films. Optical properties such as absorbance, transmittance and optical band gap were determined by Uv-Vis spectroscopy. The optical band gaps of the ppTh thin films were determined to be 2.97 eV, 3.13 eV, 3.17 eV and 3.68 eV with increasing RF power, respectively. In addition, all thin films were highly transparent in the visible region (500 nm), and this transparency tended to increase with increasing RF power. SEM analysis showed that the thin films had nanosphere structure and the radius of these spheres was about 90 nm.
- MakaleAçık Erişim2019Wettability, optical and chemical characteristics of plasma-polymerized d-limonene thin films
Bayram, Ozkan
In this study, organic based polymer thin films were obtained on various substrates using D-Limoneneessential oil, which is an organic compound by radio frequency (RF) plasma polymerization technique. Theoptical band gap and absorption spectra of thin films were investigated by Uv-VIS spectra and depending on theincreased RF power, the optical band gap of the thin films was found to be 3.19, 3.25 and 3.31 eV, respectively.WCA analyzes were also performed to determine the wettability properties of thin films and all thin films hadhydrophilic properties and these properties were significantly affected by increased RF power. Considering boththe morphological and optical properties of plasma polymerized (pp) D-Limonene thin films, it is thought thatthese films may be an alternative to those already used in current electronic applications due to their organiccompound-based nature.
AtıfTR Dizin1
İncele - MakaleAçık Erişim2019Cvd ve pecvd tekniği kullanılarak bakır folyolar üzerinde grafen nanoyapıların elde edilmesi ve karakterizasyonu
Bayram, Ozkan; İğman, Erdal; Simsek, Onder
Bu çalışmada, CH4 gazı kullanılarak bakır folyolar üzerinde grafen ince filmlerin sentezlenmesi amaçlanmıştır.İnce filmlerin elde edilebilmesi için plazma destekli kimyasal buhar biriktirme (PECVD) ve kimyasal buharbiriktirme (CVD) yöntemi kullanılmıştır. Bakır alt-taşlar, standart ön temizlik yapıldıktan sonra kuvars camdanyapılmış reaktöre yerleştirilmiştir. Vakum odasının taban basıncı 5-10 mTorr’a düşürüldükten ve hidrojen gazıile tavlama işlemi yapıldıktan sonra, CH4 gazı ortama gaz akış kontrol ünitesi yardımıyla gönderilmiştir. PECVDsisteminde; RF güç kaynağı (13,56 MHz), kontrol ünitesi vasıtasıyla aktif hale getirilerek, üretilen enerji ortamagönderilmiştir. İşlem basıncı 100 mTorr, sıcaklık 600 ˚C, RF gücü 50 W ve kaplama süresi ise 20 dakika olarakayarlanmıştır. CVD tekniğinde ise, RF gücü ortadan kaldırılmış ve büyütme sıcaklığı 1000 ˚C olarakbelirlenmiştir. Elde edilen Grafen nanoyapıların karakterizasyonu için Raman, SEM ve TEM analizlerigerçekleştirilmiştir. Raman sonuçlarına göre, CVD yöntemiyle elde edilen yapılar, tek tabaka grafen yapısınıdoğrulamıştır. Bununla beraber PECVD tekniği ile tek tabaka grafen nanoyapılardan ziyade çok tabakalı yapıelde edildi.
AtıfOpenAlex1İncele - MakaleYalnız künye2019Scopus SJRQ1Vertically oriented graphene nano-sheets grown by plasma enhanced chemical vapor deposition technique at low temperature
Bayram, Ozkan; Simsek, Onder
In this study, it was aimed to obtain vertically-oriented graphene nano-sheets (VGNs) on copper foils using CH 4 gas as the precursor material by means of plasma enhanced chemical vapor deposition (PECVD) technique. VGNs were obtained at 50 W, 75 W and 100 W Radio Frequency (RF) powers by this technique and the effect of RF power on the morphological structure of graphene layers was investigated. VGNs were also analyzed by Raman spectroscopy, scanning electron microscopy (SEM) and water contact angle (WCA) measurements. The SEM images showed that the VGNs became more tightly packed with the increase of RF power and thus these coating parameters had a significant effect on the morphological structure. WCA analyzes for VGNs were also performed and it was found that VGNs obtained at 100 W RF power had higher contact angle value than the other RF powers. These VGNs, which have both large surface area and optically transparent, are thought to be materials that have the potential to be used in supercapacitors and solar cells.
AtıfScopus19WoS17OpenAlex19İncele - MakaleAçık Erişim2019Scopus SJRQ2The role of cobalt doping on the optical and structural properties of Mn 3 O 4 nanostructured thin films obtained by SILAR technique
Bayram, Ozkan; İgman, Erdal; Guney, Harun; Simsek, Onder
Cobalt doped manganese oxide thin films (Mn 3 O 4 :Co) were successfully deposited on soda lime glass substrates using SILAR technique. Mn 3 O 4 :Co thin films were characterized using XRD, SEM, Uv–VIS and Raman spectroscopy. The XRD spectra showed that thin films had substantially Hausmannite crystal structure. The preferential orientation of the pure and 0.5 at.% Co doped manganese oxide thin films (Mn 3 O 4 ) was (002), but with increasing Co doping, it was detected that this preferential orientation shift towards the (211) plane. The absorbance, transmittance and optical band gap of the Mn 3 O 4 :Co thin films were determined using Uv–Vis spectroscopy and these properties of the thin films differed considerably due to cobalt doping. The optical band gap of pure Mn 3 O 4 thin films was 2.00 eV, but on the other hand, due to the Co doping this value increased before and then decreased slightly. Optical transmittance of Mn 3 O 4 :Co films increased from 60% to 72% with the effect of Co doping. A1g mode, which is the characteristic vibration peak of Mn 3 O 4 films, was confirmed for pure and doped Mn 3 O 4 thin films at a wavelength of 658 nm.
AtıfScopus26WoS24OpenAlex25İncele - MakaleAçık Erişim2019Scopus SJRQ2Investigation of structural, morphological and optical properties of Nickel-doped Zinc oxide thin films fabricated by co-sputtering
Bayram, Ozkan; Sener, Emre; İgman, Erdal; Simsek, Onder
In this study, it was aimed to grow Nickel doped (0.0 at.%, 0.16 at.%, 0.20 at. % and 0.24 at. %) Zinc Oxide (NZO) thin films on quartz substrates using Magnetron Sputtering technique. NZO thin films were obtained at a temperature of 450 °C, a pressure of 480 m Torr and a deposition time of 30 min. Co-sputtering process for both Ni and ZnO target was performed using two separate power sources. The DC power of the Ni target material was 20, 30 and 40 W, respectively while the radio frequency (RF) power of the Zinc oxide (ZnO) target material was set to 150 W. Using XRD analysis, thin films were found to have polycrystalline morphology, and the average crystallite size changed significantly depending on the increased Ni doping level. The optical Transmittance of the thin films was greater than 90% in the visible region (550 nm), and this value tends to decrease slightly by Ni doping. The optical band gap (E g ) firstly decreased and then slightly increased with the Nickel doping ratio and these values were found to be 3.23 eV, 3.11 eV and 3.15 eV, respectively, with increase of Ni doping.
AtıfScopus34WoS30OpenAlex37İncele - MakaleYalnız künye2019Scopus SJRQ1A study on 3D graphene synthesized directly on Glass/FTO substrates: Its Raman mapping and optical properties
Bayram, Ozkan
In this study, vertically oriented (3D) graphene nanostructures (VGN) were obtained on Glass and Fluorine doped tin oxide (FTO) substrates at relatively low temperatures (approaximatelly at 400 °C) by using plasma enhanced chemical vapor deposition (PECVD) technique. VGNs were characterized using Raman, Uv–Vis and SEM spectroscopies, respectively. Raman spectroscopy showed that growth temperature significantly affected VGN formation and film quality. The layer structures of these VGNs were also confirmed by Raman mapping. The most important data obtained from this study is that although the applied radio frequency (RF) power is the same, the growth temperature significantly affects the graphene formation and morphologies. This was attributed to the fact that CH4 decomposition was very difficult at low temperatures. The optical transmittance of VGNs ranged from 50% to 95% (at 550 nm wavelength) and their electrical conductivity was also determined to be between 5.94 kohm/sqr and 11.2 kohm/sqr. The electrical and optical properties of VGNs, which have a large surface area, indicated that they may be an alternative material for sensor, solar cell and supercapacitor applications.
AtıfScopus19WoS18OpenAlex20İncele - MakaleYalnız künye2018Scopus SJRQ2Changes of surface properties of calcite particles with calcium stearate using conventional experimental design and properties of coated calcite
Ucurum, Metin; Bayram, Ozkan; Toraman, O. Yusuf; Kilic, Habibe; Yalcin, Seyma
Calcite is utilized as a filler mineral in the industries such as plastics, rubber, and paint, to gain products with a variety of features. In order to use a calcite ore as a filler, some specific physical and physico-chemical properties are required such as ultra-fine sizes and conversion of hydrophilic to hydrophobic structure. In the present study, for these purposes, surfaces of the ultra-fine calcite powder (d50=2.94 μm) were coated by a mechano-chemical process with calcium stearate [Ca(C17H35COO)2] in a stirred ball mill. The influence of operating parameters such as calcite filling-ratio, ball-filling ratio, operation speed, grinding time and chemical dosage on the active ratio (%) was systematically examined. Then, the properties of modified calcite product were measured and evaluated by contact angle, TGA, DTA, FTIR, and SEM. The results showed that the mechano-chemical technology is very effective for modifying the surface of micronized calcite products using calcium stearate chemical.
AtıfScopus20WoS18İncele - MakaleYalnız künye2018Scopus SJRQ2Investigation of the effect of RF energy on optical, morphological, chemical and antibacterial properties of PolyTerpenol thin films obtained by RF-PECVD technique
Bayram, Ozkan; Simsek, Onder
In this study, it was aimed to obtain PolyTerpenol thin films by radio frequency plasma enhanced chemical vapor deposition technique using Terpinen-4-ol essential oil, which is organic compounds. The surface morphology and chemical properties of polymer thin films were investigated by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy. AFM analyzes of PolyTerpenol thin films revealed that the thin films are homogeneous, smooth and nonporous. The optical properties of the thin films were determined using UV–Vis spectrophotometer. When optical band gaps of thin films were examined, it was found that this value varied from 3.83 to 3.20 eV. The extinction coefficients of the obtained thin films according to the increasing RF energy were calculated as 0.0011, 0.0060, 0.0085 and 0.0150, respectively, at a wavelength of 320 nm. In addition, antibacterial effects of these thin films against Escherichia Coli (E.Coli) bacteria were also investigated. The PolyTerpenol thin films were found to have high antibacterial activity against E. Coli bacteria.
AtıfScopus8WoS8OpenAlex11İncele - MakaleAçık Erişim2018Scopus SJRQ2Synthesis and characterization of Zn-doped Mn3O4 thin films using successive ionic layer adsorption and reaction technique: Its structural, optical and wettability properties
Bayram, Ozkan; Ertargin, Mehmet Emrah; Igman, Erdal; Guney, Harun; Simsek, Onder
In this study, it is aimed to obtain Zn doped Mn3O4 (manganese oxide) nanostructured thin films on the soda lime glass substrates by successive ionic layer adsorption and reaction technique. The tetragonal crystal structure of the all thin films was detected using XRD spectroscopy. The average crystallite size of undoped Mn3O4 thin films was calculated to be 29 nm and for Zn-doped thin films, this value decreased to 23 nm with increasing Zn concentration. Characteristic peaks for thin films were also confirmed by RAMAN spectroscopy. The morphological structures of zinc-doped manganese oxide nano-sheets thin films were revealed by SEM. Using UV–Vis spectroscopy, it was found that the optical band gap of Mn3O4 thin films decreased from 2.05 to 1.73 eV with Zn doping. It has also been understood from the wettability analyzes of thin films that all thin films have a hydrophilic character. From all these analyzes, it is thought that the Zn doped Mn3O4 thin films have the potential to be used in supercapacitor applications.
AtıfScopus25WoS22OpenAlex25İncele - MakaleYalnız künye2018Scopus SJRQ1Conjugated polythiophene/Ni doped ZnO hetero bilayer nanocomposite thin films: Its structural, optical and photoluminescence properties
Bayram, Ozkan
In this study, synthesis and characterization of plasma polymerized Thiophene/ Nickel doped Zinc Oxide (PTNZO) bilayer nanocomposite films were carried out. Nickel doped zinc oxide (NZO) thin films were obtained by magnetron sputtering technique on glass substrates at 40 W Radio Frequency (RF) power. Plasma polymerized Thiophene (PT) thin films were deposited on the NZO thin films obtained on the glass substrate by Radio Frequency (RF) plasma polymerisation technique. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), FTIR and Photoluminescence (PL) analyzes were performed for the characterization of PTNZO hetero bilayer nanocomposite films. In the XRD spectra of PTNZO bilayer nanocomposite thin films, (002) planes were determined as the most basic peak, and it was determined that the intensity of this peak, changed depending on the RF power of polymer thin films. Optical properties of nanocomposite thin films such as transmittance, absorbance and optical band gap were determined by UV–Vis spectroscopy. Optical band gap for PTNZO nanocomposites were 2.72 eV, 2.34 eV, and 2.45 eV, respectively, with increasing RF power. For NZO thin films, this value is 3.12 eV. The optical band gaps calculated from the absorption and transmittance spectra obtained using UV–visible spectroscopy had a good compatibility with those of the optical band spectra calculated from the PL spectra. The tetragonal wurtzite structure of the NZO thin films was examined by SEM analysis. The grain size of NZO nanostructure was found to be approximately 59 nm.
AtıfScopus9WoS9OpenAlex9İncele