Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2015Scopus SJRQ3Optical and surface properties of LiFePO4 thin films prepared by RF magnetron sputtering
Volkan, Şenay; Özen, Soner; Pat, Suat; Korkmaz, Şadan
LiFePO4 thin films with thickness values of 65 nm and 70 nm were deposited onto glass substrates by RF magnetron sputtering, using a LiFePO4 target in the argon atmosphere. A comprehensive study of the optical properties was performed and the dispersions of the constants were determined. The transmittance and absorbance spectra were measured in the wavelength range of 400-1000 nm. The films showed optical transmittance over 90% in the visible range. The optical band gap value of the films was evaluated as 3 eV. The refractive index value of the films is 1.63 at λ = 550 nm. AFM micrographs indicate smooth surface with low values ofroot mean square roughness. Contact angle measurements of several testing liquids were used to characterize each sample in terms of wettability. The films are hydrophilic as observed from contact angle measurements. The surface free energy of the film surfaces and their components (dispersive and polar) were calculated from the contact angle data using the different theories available in the literature.
AtıfScopus14WoS12OpenAlex15
İncele - MakaleAçık Erişim2015Scopus SJRQ2Deposition of a Mo doped GaN thin film on glass substrate by thermionic vacuum arc (TVA)
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
Current research presents a new deposition method for GaN thin films that produces in a very short production time for GaN-based solid-state applications. A Mo doped GaN thin film on a glass substrate was produced by thermionic vacuum arc (TVA) technique. The TVA technique is a novel non-reactive plasma technique. The optical properties were determined by Filmetrics F20 interferometer and UV–Vis double beam spectrophotometer. The surface morphology was analyzed using field emission scanning electron microscopy and atomic force microscopy. The mean thickness value was measured as 100 nm by Filmetrics interferometer. The crystalline structure of the produced thin film has a Wurtzite crystal structure (004) as obtained by X-ray diffraction. Hardness value was determined as 14 GPa with the Oliver–Pharr method. The obtained properties are consistent with the values reported in related literature. The findings indicate that the TVA method provides advantages for optical and industrial applications.
AtıfScopus20WoS20OpenAlex22İncele - MakaleAçık Erişim2015Scopus SJRQ2Direct and fast growth of GaAs thin films on glass and polyethylene terephthalate substrates using a thermionic vacuum arc
Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan
Using a thermionic vacuum arc, single‐crystal gallium arsenide (GaAs) layers of micron thickness were grown on PET and glass substrates in 2 min. We present a new deposition mechanism and parameters for GaAs thin films produced in a very short time. Crystal direction was found to be (111) plane for the GaAs/PET sample and (022) plane and (133) plane for the GaAs/glass sample, respectively. The average roughness values of the deposited thin films were determined to be approximately 30 nm for GaAs/PET and 60 nm for GaAs/glass. The structures can be seen clearly in field emission scanning electron microscopy and atomic force microscopy. The obtained optical band is nearly the same with literatures values of the GaAs. Although produced structures in different crystal formations, only aggregations dimensions and absorbance of the layers were changed. Obtained refractive index values are nearly same with database info.
AtıfScopus16WoS18OpenAlex16İncele - BildiriYalnız künye2014Scopus SJRQ1ZnO thin film synthesis by reactive radio frequency magnetron sputtering
Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Aydoʇmuş, Tuna; Elmas, Saliha; Özen, Soner; Ekem, Naci; Balbaʇ, M. Zafer
In this study, ZnO thin films were deposited on glass substrates by reactive RF magnetron sputtering method at argon-oxygen gas mixing (1:1) atmosphere. Some properties of the synthesized films were investigated by interferometry, UV-vis spectrophotometer, atomic force microscopy, and tensiometer. Tauc method was adopted to estimate the optical band gaps. The band gaps of the deposited films were affected by film thickness. We concluded that the surface composition plays a substantial role in the values of the band gaps. Nanocrystalline structures were detected in all produced samples.
AtıfScopus55WoS49İncele