Yazar "Dere, A." seçeneğine göre listele

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    Cadmium Oxide:Titanium Dioxide Composite Based Photosensitive Diode
    (Springer, 2018) Karabulut, Abdulkerim; Dere, A.; Al-Sehemi, Abdullah G.; Al-Ghamdi, Ahmed A.; Yakuphanoglu, F.
    Cadmium oxide:titanium dioxide (CdO:TiO2) composite thin films with various ratios of CdO contents were prepared on p-type silicon semiconductor substrates by the sol-gel spin coating method. Al/CdO:TiO2/p-Si/Al heterojunction devices exhibited optoelectronic device behavior due to their photocurrent under solar light illuminations. The photoresponse behavior of the diodes is controlled by changing the molar ratio of CdO to TiO2. The fabricated CdO:TiO2 (2:1) based device exhibited the highest photoresponse of about 7.5 x 10(3). The interface properties of the devices are changed with the molar ratio of CdO:TiO2. The obtained results suggest that CdO:TiO2 composite film/p-type Si structure can be used in optoelectronic applications.
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    Cu-Al-Mn shape memory alloy based Schottky diode formed on Si
    (Elsevier, 2019) Aldirmaz, E.; Tataroglu, A.; Dere, A.; Guler, M.; Guler, E.; Karabulut, A.; Yakuphanoglu, F.
    In this work, martensite was made over the wide temperature ranges and the two forms of martensite morphology in Cu85.41Al9.97Mn4.62 shape memory alloy (SMA) were beta' and gamma' martensite phases. The SMA was characterized by the use of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. In order to fabricate the Schottky diode, Cu-Al-Mn alloy was used as a Schottky contact on p-type Si semiconductor substrate. Some of the crucial parameters for diodes such as ideality factor and barrier height values were obtained from electrical measurements. Illumination-dependent measurements showed that the fabricated device presents the behaviors of photodiode and photoconducting. Besides, it is found that the fabricated diode's structure is sensitive to illumination. Frequency-dependent measurements also indicated that the series resistance and interface state parameters are crucial to affect electrical characteristics of the fabricated diode. The experimental results showed that the fabricated Schottky device could be used in variety of optoelectronic applications.
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    CuAlMnV shape memory alloy thin film based photosensitive diode
    (Elsevier Sci Ltd, 2020) Canbay, C. Aksu; Tataroglu, A.; Farooq, W. A.; Dere, A.; Karabulut, Abdulkerim; Atif, M.; Hanif, Atif
    In the present work, the polycrystalline quaternary shape memory alloy (SMA) using composition of Cu-10.24 Al-3.13 Mn-0.41 V (wt%) was prepared with arc melting technique. The produced SMA was characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). In order to fabricate the Schottky diode, the SMA was utilized as a Schottky contact on n-Si. The admittance (Y = G thorn i omega C) measurements were performed at different frequencies while the current-voltage (I-V) measurements of the prepared diode were performed at different light intensity conditions. The reverse bias current measured under illumination was found to be greater than the condition of dark. The obtained results approve that the diode displays a photoconducting behavior. The electrical parameters of diode were calculated from I-V data. Besides, the frequency impacts on the capacitance and conductance characteristics with regards to voltage were investigated. The experiments suggest that the fabricated diode could be chosen in the applications of the optoelectronic devices.
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    Interface controlling study of silicon based Schottky diode by organic layer
    (Springer, 2019) Imer, Arife Gencer; Korkut, A.; Farooq, W. A.; Dere, A.; Atif, M.; Hanif, Atif; Karabulut, Abdulkerim
    The organic layer-on- insulator-semiconductor structures have attracted most attention owing to their great significance on technological applications. The interface of silicon based metal/semiconductor diode was improved using an organic layer. In this study, Sn/p-Si MS contact and Sn/C14H15N3/p-Si MIS heterojunction were fabricated via spin coating method. The electrical parameters of both devices have been investigated, and compared using the current-voltage (I-V) and capacitance-voltage (C-V) data at room temperature. The ideality factor of diodes with and without organic interfacial layer was calculated as 1.33 and 1.28, respectively. The values of barrier height were estimated as 0.69 and 0.81 eV for the MS and MIS type structure, respectively. Additionally, the values of series resistances for both diodes were determined as 1.27 and 1.19 k omega from Norde functions, respectively. The barrier height values were also examined using the reverse bias C-2-V characteristics for both diodes, and compared with results obtained from I to V data. The experimental results confirmed that the barrier height of Sn/C14H15N3/p-Si MIS structure is considerably higher than that of traditional Sn/p-Si MS diode. The performance and quality of these type devices could be improved and controlled by inserting the organic interfacial layer between the metal and semiconductor.
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    Photodiode based on Pb0.9Cd0.1S ternary alloy semiconductor for solar tracking systems
    (Springer, 2018) Wageh, S.; Karabulut, Abdulkerim; Dere, A.; Al-Sehemi, Abdullah G.; Al-Ghamdi, Ahmed A.; El-Tantawy, Farid; Yakuphanoglu, F.
    The fabrication and photoelectrical properties of the photodiodes based on the ternary alloy of semiconductor nanocrystallite Pb0.9Cd0.1S with coumarin dopant were investigated. The structure, stability, melting temperature and optical bandgap of the prepared nanostructure were characterized by X-ray diffraction, thermogravimetric analysis, Infrared, Raman spectroscopy and UV-VIS-NIR spectroscopies. The characterization of the ternary alloy indicates that the crystal structure of the ternary alloy is cubic with some distortion in (111) direction and has a nanosize of 9 nm. The photoelectrical characteristics of fabricated Si-based photodiodes with coumarin doped PbCdS interfacial layers were investigated by using current-voltage, transient photocurrent and capacitance/conductance-voltage measurements. Some electrical parameters and the effects of illumination on these parameters have been determined from these measurements. Consequently, results of experiments suggest that the ternary alloy Pb0.9Cd0.1S nanocrystallite based photodiode can be suitable for optoelectronic applications.
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    Photoelectrical characteristics of novel Ru(II) complexes based photodiode
    (Springer, 2019) Farooq, W. A.; Elgazzar, Elsayed; Dere, A.; Dayan, O.; Serbetci, Z.; Karabulut, Abdulkerim; Atif, M.
    The Ru(II) complex was prepared by the reaction of 4-chloro-N-[(E)-(pyridin-2-yl) methylidene] benzene-1-sulfonamide, [RuCl2(p-cymene)](2) and 2,2-(pyridine-2,6-diyl) bis(1H-benzimidazole) compounds by simple chemical technique. Al/ruthenium(II) complex/p-Si/Al was characterized by electronic devices and its electrical properties were studied as photodiode. In dark, the photodiode parameters such as potential barrier phi and ideality factor n were investigated from current-voltage (I-V) plot and confirmed by using Cheung-Cheung and Norde's models. Under illumination effect, the synthesized device shows high photosensitivity and the charge carriers increased based on the trapped state created under the conduction band. It was observed from conductance-voltage (G-V) and resistance-voltage (R-s-V) measurements that the series resistance Rs of the diode is decreased dramatically and its conductance G is increased by applied electric field.
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    SILAR Controlled CdS Nanoparticles Sensitized CdO Diode Based Photodetectors
    (Springer, 2020) Gozeh, Bestoon Anwer; Karabulut, Abdulkerim; Yildiz, Abdulkadir; Dere, A.; Arif, Bilal; Yakuphanoglu, Fahrettin
    In this research, we have produced Al/CdS nanoparticles-CdO/p-si/Al photodetetor and investigated its optical and electrical characteristics for various optoelectronic applications. The CdO thin film was covered by using sol-gel spin coating method onto the silicon, followed by CdS nanoparticles constitution by the help of SILAR technique. In order to examine the morphological and optical characteristics of fabricated photodetector, the field emission scanning electron microscopy and UV-Vis spectroscopy were utilized, and the band gap of the prepared film was determined as 2,17 eV with the help of these analyzes. The current behavior against the varying voltage values were investigated for the different intensities of solar light conditions and the significant diode parameters were computed by the use of this measurements. As a result of this computation, the barrier height value was found to be 0.49 eV while the ideality factor value was 3.2, and the photoresponse of the photodetector was measured as approximatelly 2.65 x 10(3). Besides, the transient photocurrent and photocapacitance charactersitics were examined for distinct light conditions. Finally, the interface states were calculated from the capacitance/conductance-voltage (C/G-V) measurements.
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    Silicon based photodetector with Ru(II) complexes organic interlayer
    (Elsevier Sci Ltd, 2019) Karabulut, Abdulkerim; Dere, A.; Dayan, Osman; Al-Sehemi, Abdullah G.; Serbetci, Z.; Al-Ghamdi, Ahmed A.; Yakuphanoglu, F.
    In present work, the electrical properties and illumination effects were investigated for the silicon based photodetector with organic Ru(II) complexes interfacial layer. The current-voltage (I-V) and capacitance/conductance-voltage (C/G-V) measurements were analyzed to determine electrical and photoelectrical properties under dark and different solar light intensity conditions. The reverse bias current values under light conditions were higher than dark conditions, and this situation demonstrates that the fabricated device displays a photo conducting behavior. Besides, some crucial electrical parameters such as series resistance, barrier height and ideality factor values of prepared device were calculated by using current-voltage measurements. The ideality factor and barrier height values of fabricated device were calculated as 9.42 and 0.59 for dark condition. Besides to these experiments, transient photocurrent and photo-capacitance/conductance were also investigated under different light conditions. It was determined from transient measurements that the fabricated device has a high sensitivity to light. The photoresponse of the diode was determined to be around 4479 +/- 1.9 under 100 mW/cm(2 )illumination. The examined C/G-V characteristics of the fabricated device strongly depend on voltage and frequency. The analyzed results suggest that the fabricated Al/Ru(II) complexes/p-Si/Al device can be used in rapidly developing optoelectronic applications, especially for the organic materials-based photodetector technology.