Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/11422
  CMTS: An inorganic hole-transport material for efficient and stable perovskite solar cells through surface defect passivation

  Sari, Fahriye; Ozel, Sultan Suleyman; Ozel, Faruk; Kus, Mahmut; Wilton, Richard Hall

  A major challenge in PSCs lies in the carrier transport losses induced by band misalignment and elevated series resistance, which adversely impact the fill factor and device stability, ultimately restricting the overall power conversion efficiency. Due to their tunable band gaps, low fabrication cost, strong light-harvesting capability, adequate carrier lifetime, chemical stability, and environmentally benign nature, chalcogenide perovskites have emerged as highly promising materials for optoelectronic applications. In this study, the quaternary semiconductor nanostructure Cu2MnSnS4 (CMTS) was synthesized via a simple and cost-effective hot-injection method and investigated as an alternative inorganic hole transport layer (HTL) candidate. Indium tin oxide-based perovskite solar cells without any metal oxide interlayer achieved a remarkable PCE of 9.87% and retained more than 92% of their initial efficiency after 720 hours, demonstrating enhanced stability. These findings highlight the critical role of cation–anion interactions in improving device stability and underscore the importance of developing innovative, low-cost, and efficient inorganic HTL materials for the commercial advancement of perovskite solar cells.

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  İncele
• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/11359
  Exploring the ımpact of metal doping and alternative electrodes on the performance of dye-sensitized solar cells

  Calıskan, Berrak; Sayan, Enes; Igman, Erdal

  This study explores the synthesis and characterization of metal-doped TiO2 thin films for applications in dye-sensitized solar cells (DSSCs). Titanium dioxide (TiO2) films were doped with various metal ions such as Ag+, Zn2+, Fe3+, and Co2+, to enhance the photoelectrochemical properties of the photoanode. The films were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS). The doping process was found to influence the morphology, surface area, and optical properties of the TiO2 films, resulting in enhanced light absorption, particularly in the visible range. The effects of metal doping on the performance of the DSSCs were evaluated, showing that Co2+ and Ag+ doping resulted in improved efficiency compared to undoped TiO2, with the Co2+-doped TiO2 achieving the highest power conversion efficiency of 2.85%. Additionally, the incorporation of reduced graphene oxide (rGO) as a counter electrode demonstrated a significant enhancement in DSSC performance, even surpassing traditional platinum-based counter electrodes. The results suggest that metal doping and rGO incorporation offer promising strategies for improving DSSC efficiency. This study highlights the potential of metal-doped TiO2 photoanodes and rGO counter electrodes in advancing the development of cost-effective, high-performance DSSCs for sustainable solar energy applications.

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  AtıfScopus1·WoS1

  İncele
• MakaleAçık Erişim2025Scopus SJRQ2/r/bayburt/14287
  Investigation of the memristive properties of the device form and thin film form of BST and CeO2 films with different arrays

  Akin, Ozlem; Efeoglu, Hasan

  In this study, a memristor structure known as a missing circuit element was produced. This study consists of a total of six samples in both thin film and device form with different arrays of BST film and CeO2 film on SiO2/Si substrate. The effects of different arrays and device forms of these two films on memristive behavior were investigated. It was observed that the structures exhibited memristive behavior due to the difference in ion mobility in films with different dielectric constants. It was also observed that the structures changed their memristive behavior in the annealing process performed at different temperatures. It was observed that the memristive behaviors examined imitated the connection strength of artificial synapses, and they are suitable for the production of multi-bit memristors or analog memristors suitable for the creation of artificial neuromorphic networks.

  İncele
• MakaleAçık Erişim2025Scopus SJRQ2/r/bayburt/11311
  The structural, optical, topographical, and H2 sensing characteristics of a Zn-doped Fe2O3 thin layer deposited via DC & RF magnetron co-sputtering method

  Merhan Muğlu, Günay; Şenay, Volkan; Saritaş, Sevda; Abdolahpour Salari, Maryam; Kundakçi, Mutlu

  In this study, a Zn-doped iron oxide layer was deposited onto a microscope slide using the magnetron co-sputtering technique with direct current (DC) and radio frequency (RF) sources. We comprehensively characterized the resulting Zn-doped Fe2O3 thin layer, employing techniques such as XRD, Raman spectroscopy, UV–VIS spectrophotometry, SEM, EDX, & AFM. XRD examination showed the nanocrystalline structure in the thin layer under investigation. Based on recorded absorption data, the band gap energy value calculation resulted in a value of 2.23 eV for the thin film. Raman spectroscopy identified peaks possessing Raman shifts from 100 to 1400 cm−1. SEM investigation illustrated a consistently uniform thin film surface characteristic throughout the substrate. Additionally, the AFM study disclosed a small RMS roughness value, indicative of an unrough surface for the Zn: Fe2O3 thin layer. The Fe2O3 thin film doped with Zn employing a 30 W DC voltage demonstrated effective hydrogen sensing capability at 300 °C, achieving notable response and recovery time. This work presents a novel application of Zn-doped Fe2O3 thin films as highly sensitive and stable hydrogen sensors, tailored for high-temperature environments. The unique combination of nanocrystalline structure and Zn doping optimizes the material’s electronic properties, enhancing its responsiveness to hydrogen gas. This approach offers a scalable, cost-effective pathway for developing advanced sensor technologies suited to environmental monitoring, industrial safety, and hazardous gas detection, making it a valuable addition to the field of gas-sensing materials.

  AtıfScopus19·WoS19·OpenAlex11

  İncele
• MakaleAçık Erişim2024Scopus SJRQ2/r/bayburt/11065
  Electrical properties of Al/CZTSe nanocrystal Schottky diode

  Kişnişci, Z.; Özel, F.; Karadeniz, S.; Tuğluoğlu, N.; Özel, S.S.; Yüksel, Ö.F.

  In this study, electrical changes in diode parameters of Schottky diodes that made of a kesterite semiconductor were examined under different temperatures. For this aim, Cu2ZnSnSe4 (CZTSe) nanocrystals were fabricated using the hot injection technique, and it was covered by spin coating on an ITO glass substrate. We was introduced the physical and structural analyses using scanning electron microscopy and X-ray spectroscopy. Current–voltage measurements were fulfilled at different temperature (from 100 to 325 K) under dark environment. It was observed that its electrical parameters were strongly affected by temperature.

  AtıfScopus11·WoS10·OpenAlex10

  İncele
• MakaleYalnız künye2023Scopus SJRQ2/r/bayburt/13125
  Cr-substituted nanocrystalline Ni–Co ferrites: tuning dielectric, magnetic, structural, X-band microwave absorption, and characteristic properties

  Teber, Ahmet; Sarac, Mehmet F.

  The structural, characteristic, dielectric, and magnetic features of Co0.5Ni0.5CrxFe2 − xO4 (0.0 ≤ x≤ 1.0 with a step of 0.2 x-concentration) nanoparticles are prepared via the hydrothermal method. The investigation of characteristics, structural, and magnetic features of the produced nanoparticles are examined through XRD, FT-IR, SEM–EDS, TEM-SAED, and VSM, respectively. AC conductivity and the dielectric investigations are also reported. According to the XRD measurements, all samples have the M-type hexagonal crystal structure nanocrystallites of between 27 and 97 nm. Refined structural parameters using Rietveld analysis are carried out using the TOPAS refinement program. A good match was observed between the diffraction patterns obtained and calculated by Rietveld analysis. Moreover, the morphological analyses indicate that the relatively small spherical structures of Ni–Co ferrites particles can be seen to change from spherical to relatively oval-shaped with increasing chromium content. The results of the FT-IR study show that the spinel structure has formed as predicted because the expected range of absorption bands is present. According to magnetic measurements, Cr-substituted Ni–Co ferrite nanostructures reveal a relatively soft ferromagnetic property. The coercive field (Hc) variation has a propensity to decrease in relation to the Cr-concentration. The electromagnetic constitutive parameters are calculated from measured S-parameters (S11 and S21) using network analyzer and the return losses of the samples are then obtained to determine microwave absorption properties. According to the dielectric and magnetic tangent losses or dissipation factors, both dielectric and magnetic features can mutually reinforce in terms of microwave absorption properties in the X-band. The Cr2O3 impurity peaks obtained by XRD analysis have an effect on the microwave absorption properties. The results of the microwave absorption based on each concentration reveal that there exist electromagnetic wave absorptions between approximately 11 GHz and 12.4 GHz in the X-band. The absorption trend is also towards the Ku-band.

  AtıfScopus3·WoS3·OpenAlex3

  İncele
• MakaleAçık Erişim2021Scopus SJRQ2/r/bayburt/13522
  Photoluminescence 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.

  AtıfScopus5·WoS4·OpenAlex5

  İncele
• MakaleYalnız künye2020Scopus SJRQ2/r/bayburt/13336
  Electrical 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.

  AtıfScopus25·WoS23·OpenAlex23

  İncele
• MakaleAçık Erişim2020Scopus SJRQ2/r/bayburt/12153
  Graphene/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%.

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  AtıfScopus33·WoS25·OpenAlex29

  İncele
• MakaleAçık Erişim2019Scopus SJRQ2/r/bayburt/12521
  Some physical properties of nanostructured Al doped ZnO thin films synthesized by RF magnetron sputtering at room temperature

  Şenay, Volkan

  In this research, AZO thin films were deposited on glass substrates with 70 W, 100 W and 125 W RF powers at room temperature by RF magnetron sputtering technique. The structural, optical and surface properties of the produced thin films were investigated. According to the obtained results, the investigated thin films had a crystalline structure and they showed high transparency in the visible region. The increase of RF power produced thicker films. Relatively thicker AZO films produced with higher RF power exhibited greater number of interference fringes in the reflectance and transmittance spectra. The refractive index values of the film produced with 125 W RF power were considerably lower than those of the films produced with 70 W and 100 W due to the decreased packing density. The optical energy band gap values of the produced AZO thin films were higher than that of undoped ZnO films. This expansion resulted from the Burstein–Moss effect. However, the band gap energy value as well as the roughness of the film surface decreased like refractive index with an increase in RF power, especially after 100 W. As a result, the values corresponding to the optical and surface properties can be tuned and AZO thin films can be produced by RF magnetron sputtering technique as promising candidates for optoelectronic devices and transparent conductive oxide applications.

  AtıfScopus14·WoS14·OpenAlex13

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