Çayir Taşdemirci, Tuba

Herein, manganese sulfide (MnS) thin films are grown on glass substrates using the successive ionic layer adsorption and reaction (SILAR) method. SILAR is simple and inexpensive, does not require a high-quality substrate or vacuum environment, has no limitation on the size of the substrate material, has the ability to obtain materials at room temperature, shows easier doping process relative to other methods, and has the ability to control the growth rate and thickness of films. MnS with different thicknesses is coated on a glass surface, and various analyses are performed to examine the effect of the thickness on the film properties. Ultraviolet–visible analysis is used to examine the optical properties of the film, X-ray diffraction (XRD) spectrometry to examine its structural properties, and scanning electron microscopy and atomic force microscopy (AFM) to examine its morphological properties. XRD results indicate that the obtained MnS thin films have a cubic structure and achieve the highest peak intensity at 2θ = 32.87°. With increasing film thickness, the grain size increases from 9.20 to 13.36 nm and the energy band gap decreases from 3.32 to 3.02 eV. AFM results demonstrate that with increasing film thickness, the surface roughness value decreases from 84 to 53 nm. Moreover, increasing thickness improves the optical, structural, and morphological properties of the film.

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.

Uğurlu, Mine; Akkuş, Tuba; Demir, Lütfü

Some fifth-period elements Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag and Cd have been obtained in powder form and converted into pellets by applying pressure (~ 1 GPa). They have annealed at 1000 °C (except Cd ~ 300 °C). In the external magnetic fields (0.4 and 0.8 T) and without magnetic field, the coherent to Compton differential cross-sectional ratios has been investigated by using energy-dispersive X-ray fluorescence system. The data were analyzed via Origin 9.0 computer program. The results were calculated experimentally and theoretically. The theoretical results were obtained with two different methods, and these results were compared with the experimental results. These methods are relativistic form factor theory and non-relativistic form factor theory at without magnetic field. It was seen that the coherent to Compton differential cross-sectional ratios of the elements used in the present study increases with the increasing of the magnetic field and atomic number.

Gullu, Omer; Cankaya, Murat; Rajagopal Reddy, V.

In the present work, the surface morphology, structural and optical features of graphene oxide (GO) films are investigated. The Al/GO/n-InP MIS diode is formed by depositing GO layer on n-InP wafer for the barrier enhancement. Interfacial properties of the MIS diode with GO interlayer are extracted from current–voltage (I–V) measurement. The simple diode parameters such as barrier height and ideality factor are extracted from I–V plots, and the values are compared with those of conventional Al/n-InP MS contact. The value of barrier height (BH) for the Al/GO/n-InP contact is found as 0.85 eV. The BH value of 0.85 eV of the Al/GO/n-InP MIS structure is as high as around 100% compared to the value of 0.43 eV of the Al/n-InP reference contacts. We have showed that the value of 0.85 eV is one of the highest values presented for reference contacts with an interlayer.