Yazar "Baydilli, Esra Evcin" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • Küçük Resim Yok
    Öğe
    Determination of temperature sensitivity and current-transport mechanisms of the GaAs-based MS contact
    (Elsevier, 2023) Kaymaz, Ahmet; Baydilli, Esra Evcin; Tecimer, Hueseyin; Tecimer, Habibe Uslu; Altindal, Semsettin
    In this study, the GaAs-based metal-semiconductor (MS) contact was prepared as a reference sample for com-parison with other devices in the literature, especially some interfacial layered Schottky structures and tem-perature sensors. The study also includes investigating and evaluating essential device parameters for determining current-transport mechanisms (CTMs) and temperature-sensing behavior. In fact, the benefits of the insulator/organic interfacial layer in devices, such as controlling charge transfers and preventing diffusion at the MS interface, have been mentioned a lot in the literature. However, since the production processes of the MS contact are easier and less costly than interfacial-layered devices, it would be more logical/suitable to prefer it in applications where this device may be sufficient, especially as a temperature sensor. Therefore, the current-voltage (I-V) data of the produced MS contact was obtained in a wide temperature range to determine the CTMs, and it was observed that two linear areas with different slopes, known as the two-parallel diode model, existed in the GaAs-based MS contact. Therefore, essential contact parameters and graphs were obtained for both two regions, and it was obtained that quantum mechanical tunneling mechanisms, the T0 effect, and the Double Gaussian Distribution (DGD) with Thermionic Emission theory play a role as CTMs of the GaAs-based MS contact such as some interfacial layered devices given in the literature. On the other hand, the temperature sensitivity of the MS contact was examined, and it was observed that the sensitivity parameter values exhibit an excellent quality sensing behavior compared to other devices in the literature, including devices with high-temperature sensitivity. Therefore, it can be preferred as a temperature sensor in many applications due to its low cost and easy production processes.
  • Küçük Resim Yok
    Öğe
    Evaluation of gamma-irradiation effects on the electrical properties of Al/(ZnO-PVA)/p-Si type Schottky diodes using current-voltage measurements
    (Pergamon-Elsevier Science Ltd, 2021) Kaymaz, Ahmet; Baydilli, Esra Evcin; Tecimer, Habibe Uslu; Altindal, Semsettin; Azizian-Kalandaragh, Yashar
    In this study, Al/(ZnO-PVA)/p-Si (MPS) type Schottky diodes (SDs) were produced and the radiation effects on their electrical properties were investigated using the current-voltage (I?V) measurements. The I?V measurements were performed before irradiation and after various irradiation doses in the wide voltage range (?4 V) at room temperature. To determine gamma-irradiation effects on the MPS-type SDs accurately, one SD was preferred as a sample, and its significant electrical parameters such as zero-bias barrier height (?B0), ideality factor (n), and reverse-saturation-current (I0) were calculated using the linear parts of the ln(I)?V characteristics. Besides, to observe the effects of gamma-rays on MPS-type SDs in different voltage regions, some diode parameters were obtained by different calculation methods such as Cheung and Norde functions as well as Thermionic Emission (TE) theory. The calculations showed that high doses of gamma-irradiation (>5 kGy) caused the annealing effect, which leads to an improvement in some electrical parameters of SD, especially in the high electric field region. On the other hand, the energy distribution of the surface states (Nss) was obtained by utilizing the voltage-dependent ideality factor and the effective barrier height, with and without considering the series resistance (Rs) effect. It was observed that Nss values decreased almost as exponentially from the mid-band gap of the semiconductor towards the upper edge of the valance-band. Also, the density of surface states decreased with increasing radiation doses. As a result, almost all diode parameters are affected by irradiation. However, no significant defect has been detected that would affect the stable operation of the diode. Hence, Al/ (ZnO-PVA)/p-Si type SD can be used as an MPS-type detector instead of MIS/MOS-type detectors due to some advantages of the organic/polymer interlayer such as being cheap, light per molecule, flexible and requiring low energy consumption.
  • Küçük Resim Yok
    Öğe
    Fabrication and characterization of Bİ-2212 superconducting seramic thin films
    (Karabük Üniversitesi, 2014) Baydilli, Esra Evcin; Anutgan, Mustafa; Belenli, İbrahim
    Bu tez çalışmasında elektriksel ve yüzey morfolojik özellikleri yüksek Bi-2212 ince film elde etmek için uygun üretim parametrelerinin belirlenmesi amaçlanmıştır. Kaplama yöntemi olarak kullanılan DC püskürtme yöntemi için DC güç, alttaş sıcaklığı ve kaplama süresi parametreleri incelenmiştir. Ayrıca kaplanan filmlerin uygun tavlama parametreleri belirlenmiştir. Filmler 15W DC güç ve 500 °C alttaş sıcaklığı hem 2 saat hem de 0.5 saat sürede üretilmiştir. Kaplanan filmler 845 °C, 850 °C, 855 °C, 856 °C, 858 °C, 860 °C, 862 °C, 864 °C, 865 °C, 870 °C ve 880 °C sıcaklıklarında tavlanarak, 700 °C'de sıcaklığı dindirilerek uygun tavlama sıcaklığı belirlenmesi hedeflenmiştir. Ayrıca, 860 °C'de tavlanan filmler 700 °C, 740 °C, 780 °C, 800 °C, 820 °C, 840 °C ve 860 °C'de sıcaklığı dindirilerek dindirme sıcaklığının filmler üzerindeki etkisi incelenmiştir. Kaplanan filmlerin 0,1 mA akım ile direnç-sıcaklık ölçümü yapılmıştır. Ayrıca XRD ölçümleri ile filmlerin kristal yapısı, SEM görüntüleri ile de yüzey morfolojisi incelenmiştir.
  • Küçük Resim Yok
    Öğe
    Investigation of gamma-irradiation effects on electrical characteristics of Al/(ZnO-PVA)/p-Si Schottky diodes using capacitance and conductance measurements
    (Springer, 2020) Kaymaz, Ahmet; Tecimer, Habibe Uslu; Baydilli, Esra Evcin; Altindal, Semsettin
    In this study, Al/(ZnO-PVA)/p-Si (MPS type) Schottky diodes (SDs) were fabricated instead of metal-semiconductor (MS) type SDs with traditional insulator interfacial layer. Additionally, basic electrical parameters of these MPS-type SDs (such as doping acceptor atoms (N-A), depletion layer width (W-D), series resistance (R-s), barrier height (phi(B)), and surface states/traps (N-ss/N-it)) were found as a function of gamma-irradiation by using the capacitance/conductance-voltage (C/G-V) measurements. These measurements under 0-60 kGy radiation doses show that radiation-induced N-ss are more effective in the depletion layer. On the other hand, voltage-dependent profiles of R-s and N-ss were also obtained using Nicollian-Brews and Castagne-Vapaille methods, respectively. Additionally, the C/G-V characteristics were corrected before irradiation and after 60 kGy doses by considering the effects of R-s. These calculations show that R-s is more effective especially in the accumulation region and therefore, it must be considered in the calculations. All these results have indicated that MS-type SDs with (ZnO-PVA) polymer interfacial layer are very sensitive to gamma-irradiation. Hence, they can be successfully used as MPS-type detectors instead of MIS/MOS-type detectors. Hence, they can be successfully used as MPS-type detectors instead of MIS/MOS-type detectors, since polymer layers can be easily grown compared to insulator/oxide layers. Also, they are cheaper, lighter, more flexible, and require low energy consumption. In conclusion, it can be said that although all parameters were affected by gamma-irradiation, no significant defect/deterioration was observed in applied dose range which would hinder the operation of these MPS-type SDs.
  • Küçük Resim Yok
    Öğe
    Overview of the irradiation-dependent behaviour of the negative dielectric properties of GaAs-based MIS devices
    (Pergamon-Elsevier Science Ltd, 2024) Baydilli, Esra Evcin; Kaymaz, Ahmet; Altindal, Semsettin
    In this study, negative dielectric properties of the natural oxide interfacial-layered metal-insulator-semiconductor (MIS) type structure have been investigated under different radiation doses. Some essential parameters of the GaAs-based MIS structure, such as dielectric constant (e '), dielectric loss (e) and loss factor (tan6), were obtained from the capacitance/conductance-voltage (C-G/w-V) data for before and after radiation to investigate the effects of gamma-rays on the dielectric properties of the device. Measurements were performed in the voltage range of +/- 4 V, 500 kHz frequency and at room temperature for before irradiation and after 5 and 10 kGy radiation doses to obtain C-G/w-V data under various conditions. On the other hand, the voltage-dependent variation of the ac-conductivity (aac) and complex electric modulus (M*) (including its real (M ') and the imaginary (M '') parts) of the structure were calculated before and after radiation. As a result, the peaks at approximately 1.75 V were observed in the voltage-dependent variation of the dielectric constant before irradiation and after all radiation doses. It was also observed from this point that the dielectric constant quickly took negative values, and these behaviours were attributed to the structure's differential change of charge, polarization, and electrical resonance. However, there was no significant change in the radiation-dependent dielectric properties of the structure up to the abnormal peak values. In conclusion, it can be said that although the device is generally resistant to ionizing radiation, it exhibits significant change behaviour in the negative dielectric region. This result means that when the device is operated under appropriate conditions, it can respond as a radiationresistant rectifier diode or electronic device that can benefit from its negative dielectric properties.
  • Küçük Resim Yok
    Öğe
    The Role of Co/Zn-Doped Organic Interlayer on the Operating Performance of Schottky Devices as an Ionizing Radiation Sensor
    (Ieee-Inst Electrical Electronics Engineers Inc, 2024) Kaymaz, Ahmet; Baydilli, Esra Evcin
    This study was carried out to investigate the suitability of a Schottky device with a Co/Zn-doped organic interlayer polyvinyl alcohol (PVA) for use in radiation environments such as space (satellite systems) or nuclear plants. The current and capacitance-conductance data were obtained before and after radiation exposure and for some specific days after irradiation to understand whether the device is suitable for use as a rectifier contact or an ionizing radiation sensor, especially for satellite systems. Thus, it was observed that the current parameters tended to return to their original state in the early days, although the device showed a significant response to gamma rays. On the other hand, it was observed that the parameters obtained from the impedance spectroscopy methods remained stable for a while after radiation and then tended to approach their initial state. These behaviors occur due to the relaxation time of the radiation-induced surface states, and these sensitive parameters cannot prevent the device from being used as a radiation sensor or rectifier contact (i.e., MPS-type Schottky diode). As a result, it can be said that the device is a good candidate for use as a radiation sensor at first glance. However, these pieces of information are insufficient to use the device as a commercial sensor, and the device must successfully pass further experimental tests to decide this result.