Yazarlar
- Şenay, Volkan(9)
- Pat, Suat(8)
- Özen, Soner(8)
- Korkmaz, Şadan(7)
- Geçici, Birol(3)
- Kundakçı, Mutlu(2)
- Sarıtaş, Sevda(2)
- Abdolahpour Salari, Maryam(1)
- Aydoʇmuş, Tuna(1)
- Balbaʇ, M. Zafer(1)
- Bayram, Sinan(1)
- Ekem, Naci(1)
- Elmas, Saliha(1)
- Korkmaz, Šadan(1)
- Merhan Muğlu, Günay(1)
- Muğlu, Günay Merhan(1)
- Salari, Maryam Abdolahpour(1)
- Šenay, Volkan(1)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ1Evaluation of the optical, structural, and morphological characteristics of a Sn-doped α-Fe2O3 thin film fabricated using RF and DC magnetron Co-sputtering technique
Salari, Maryam Abdolahpour; Şenay, Volkan; Muğlu, Günay Merhan; Sarıtaş, Sevda; Kundakçı, Mutlu
In this research, a Sn-doped hematite (α-Fe2O3) thin film on a glass substrate was synthesized using DC and RF magnetron sputtering techniques, and the physical features of the film were analyzed in detail. This study, conducted to investigate the effects of Sn doping on the hematite structure, evaluated the optical and morphological attributes of the thin film using advanced characterization techniques such as UV–VIS spectroscopy, Raman spectroscopy, XRD, SEM, EDS, and AFM. The optical band gap was determined from absorption measurement and calculated to be 2.12 eV. Raman spectroscopy results revealed various characteristic peaks between 100 cm−1 and 1500 cm−1. A strong (214) diffraction peak confirms the enhanced hematite phase formation in the thin film. The crystallite size of the Sn-doped thin film, calculated via Scherrer's formula, is 20 nm. SEM images showed that the thin film exhibited a smooth and homogeneous surface morphology on the glass substrate. According to the EDS results, the atomic doping ratio of Sn in Fe2O3 is 2.84 %. Additionally, AFM analysis confirmed that the Sn-doped α-Fe2O3 thin film had a smooth surface, as indicated by a low RMS (Root Mean Square) roughness value of 8.11 nm. These properties suggest that the thin film could be suitable for optoelectronic applications. The study emphasizes the potential of Sn-doped α-Fe2O3 thin films, particularly for optoelectronic and photocatalytic devices, and underscores the need for further investigation of these materials. Furthermore, it was concluded that these materials should be considered in a broader context for their potential use in various technological applications.
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İncele - MakaleAçık Erişim2024Scopus SJRQ1Analysis of optical, structural, and morphological properties of a Ti-doped α-Fe2O3 thin film produced through RF and DC magnetron Co-sputtering
Abdolahpour Salari, Maryam; Merhan Muğlu, Günay; Şenay, Volkan; Sarıtaş, Sevda; Kundakçı, Mutlu
In this study, a Titanium (Ti) doped α-Fe2O3 (hematite) thin layer was synthesized onto a glass substrate, employing the simultaneous DC and RF magnetron sputtering method. The investigation focused on examining specific physical properties of the film. The optical, structural, morphological, and elemental features of the resulting Ti-doped α-Fe2O3 thin film were characterized using different characterization techniques. The XRD studies indicated a rhombohedral crystal structure in the studied thin film. The calculation of the Eg value for the thin film, based on absorption measurements, resulted in a value of 2.19 eV. Raman peaks were identified within the range of 218 cm−1 to 1300 cm−1. According to SEM images, the thin film exhibited a uniform surface morphology across the substrate. AFM images revealed a low root mean square (RMS) roughness value, indicating a smooth Ti:Fe2O3 thin film surface.
AtıfScopus24WoS25OpenAlex29İncele - MakaleAçık Erişim2022Scopus SJRQ3A comparative characterization study between fungal and bacterial eumelanin pigments
Bayram, Sinan
Melanins are the most common and the most enigmatic natural pigments in the nature that found in many different taxa group such as bacteria, yeasts, fungi, insects, plants, reptiles, birds and mammals. These biological macromolecules are highly complex cross-linked, heterogeneous biopolymers and composed of polymerized phenolic and/or indolic compounds. Recently, interest in these ubiquitous biopolymers has been increasing considerably in many different areas such as medicine, pharmacology, cosmetics, organic electronic and optoelectronics because of their versatile properties. In this study, four different extracellular eumelanin pigments (two bacterial eumelanins and two fungal eumelanins) were characterized by different spectrometric techniques such as FT-IR, XRD, NMR and UV-vis. In XRD analyzes, purified fungal and bacterial eumelanin pigments were characterized by giving a wide peak at about 22o with an angle of 2θ. Furthermore, in the 1 H NMR spectra of these biopolymers, it was observed that all pigments have signals in both aromatic and aliphatic regions. In addition to these analyzes, nanostructures of these biopolymers were characterized using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Finally, eumelanin pigment producer microorganisms were molecularly characterized. 16 S rDNA and 18 S rDNA sequence analysis results of these microorganisms (Streptomyces fulvissimus MPPS4, Streptomyces xiamenensis MPPS6, Aspergillus niger MPPF16 and Aspergillus terreus MPPF25) were deposited in NCBI GenBank® database with accession number MT825594, MT973972, MW652652 and MW652653 respectively.
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İncele - 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 - 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 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 - 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.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2016Scopus SJRQ2Optical, morphological and mechanical properties of an Al-Al2O3 nanocomposite thin film grown by thermionic vacuum arc
Şenay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Şadan
An Al-Al2O3 nanocomposite thin film was deposited onto a glass substrate in high vacuum condition using Al2O3 pellets as source material by means of the thermionic vacuum arc technique in just 50 s. UV-visible spectrophotometer, optical reflectometer, spectroscopic ellipsometer, XRD, FESEM and AFM were employed to investigate the optical, structural morphological and mechanical properties of the produced film. The film exhibited a high transmittance (above 80%) in the 400-1000 nm region. The dispersion of the refractive index was discussed in terms of the single oscillator model. The optical band gap value derived from the Wemple-DiDomenico dispersion relationship was 5.7 eV. It was observed that the results of the optical investigations agreed well with Al2O3 thin films. XRD characterization showed that the film contained Al and Al2O3 phases. The FESEM analysis revealed that the film morphology had a dense characteristic. 2D and 3D AFM micrographs indicated a smooth surface with a low value of average roughness. When compared to the mechanical properties of Al2O3 thin films, it was observed that the hardness and Young's modulus reduced due to presence of ductile Al particles.
AtıfScopus9WoS8OpenAlex11İncele - MakaleYalnız künye2015Scopus SJRQ3A 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.
AtıfScopus8WoS7İncele - MakaleYalnız künye2015Scopus SJRQ2Some physical properties of a Si-doped nano-crystalline GaAs thin film grown by thermionic vacuum arc
Şenay, Volkan; Özen, Soner; Pat, Suat; Korkmaz, Şadan
Abstract A 160 nm thick Si-doped nano-crystalline GaAs film was grown on a glass substrate by means of the thermionic vacuum arc in just 50 s. Tools and techniques such as an optical reflectometer, Uv-Vis-NIR spectrophotometer, XRD, FESEM, AFM, Hall effect measurement, and diiodomethane, ethylene glycol, formamide, and water contact angle measurements were employed to investigate some of the physical properties of the produced film. XRD characterization indicated that the film contained GaAs (hexagonal system in atomic ratio of 1) and SiAs (monoclinic system in atomic ratio of 1) phases. The grain size obtained from Scherrer's Formula was in the range of 30-40 nm. The AFM micrographs showed the film topography, revealing a surface root mean square roughness of 14.5 nm and average height of 48.3 nm. From the wetting experiments, it was found that the contact angle value is strongly dependent on the liquid used.
AtıfScopus20WoS18OpenAlex21İncele - MakaleYalnız künye2015Scopus SJRQ3Some physical properties of the SiGe thin film coatings by thermionic vacuum arc (TVA)
Özen, Soner; Pat, Suat; Şenay, Volkan; Korkmaz, Şadan; Geçici, Birol
SiGe thin films were deposited on glass and PET substrate by the thermionic vacuum arc (TVA) method for the first time. TVA is an anodic plasma generator which works in high vacuum conditions. Highly pure and quality films can be deposited on different substrates by means of this method. In order to characterize the produced films, X-ray diffraction, field emission scanning electron microscope (FESEM), atomic force microscope (AFM), energy dispersive X-ray spectrometer (EDX), optical tensiometer, UV-Vis spectrophotometer and spectroscopic ellipsometer (SE) devices were used. The obtained XRD peaks at 47° and 75° are described to the reflections of (220) and (331) planes of Ge or Si. According to the measurement results, substrates materials are affect the surface and optical properties of the deposited SiGe layers. SiGe coated samples with low optical band gaps exhibit low transparency and high absorption. The structures are homogenous and less rough.
AtıfScopus15WoS16OpenAlex14İncele