Yazar "Yakuphanoglu, F." 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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    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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    Öğe
    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.