Browsing by Author "Yakuphanoglu, F."

Now showing 1 - 4 of 4

Controlling of the Photosensing Properties of Al/Dmy Heterojunctions by the Interface Layer Thickness
(Elsevier Science Sa, 2016) Imer, A. Gencer; Karaduman, O.; Yakuphanoglu, F.
Organic-inorganic heterojunction was fabricated by inserting an interlayer having with three different thicknesses on the p-Si substrate. The current voltage (I-V) data of different samples were measured both under the dark and solar simulator at 300 K. The photosensing properties of devices were analyzed as a function of incident light intensity via I-V data by considering the influence of different light intensity on the generated electron-hole pairs. The transient photocurrent measurement confirmed that the photocurrent is sensitive to the illumination intensities. The obtained results confirmed that photo sensing nature and responsivity of heterojunctions enhance with the illuminations. The electrical characteristic of different heterojunctions was also obtained from voltage dependent capacitance (C-V), conductance (G-V) data as a function of frequencies. The excess capacitance could not be observed at highly enough frequencies because of that interface states charge cannot follow ac signal. The density of interface states (D-it) was evaluated by Hill-Coleman method and changes in the range from similar to 1.05 x 10(12) to 9.69 x 10(10) eV(-1) cm(-2) with the increasing frequency. It is declared that, photosensing property of diode can be controlled by various thickness of the interface layer. (C) 2016 Elsevier B.V. All rights reserved.
Illumination Impact on the Electrical Characteristics of Au/Sunset Yellow/N-si Hybrid Schottky Diode
(Springer, 2020) Imer, A. G.; Kaya, E.; Dere, A.; Al-Sehemi, A. G.; Al-Ghamdi, A. A.; Karabulut, A.; Yakuphanoglu, F.
In this study, semiconductor device applications of organic material sunset yellow (SY) (C16H10N2Na2O7S2) has been investigated. The SY thin film was grown onn-Si via spin coating method and theAu/SY/n-Si/Auheterojunction was fabricated. The basic diode parameters of device were determined by the current-voltage (I-V) and capacitance-voltage (C-V) measurements at the room temperature. The values of the ideality factory (n) and barrier height (phi(b)) were evaluated as 1.15 and 0.70 eV, respectively; and series resistance (R-s) of device was found using Norde functions. The values of built in potential, donor concentration, Fermi energy level and barrier height were also estimated from the linearC(-2)-Vcurves with reverse bias room temperature and difference frequency. Furthermore,I-Vmeasurements were applied under different illuminations; some photoelectrical parameters of device were evaluated to understand the photo response properties of the device. Consequently, the results confirmed that the barrier height can be modified by interfacial SY layer, and the device can be used in optoelectronic applications such as optical sensor or photodiode.
The Photodetection Properties of a Ruthenium Electro-Optic Device for Organic Material-Based Device Industry
(Elsevier, 2023) Imer, Arife Gencer; Dere, Aysegul; Kaya, Esra; Al-Sehemi, Abdullah G.; Dayan, Osman; Al-Ghamdi, Ahmed A.; Yakuphanoglu, F.
The electrical properties and effect of illumination on the photodetection properties were investigated for the fabricated device with Ru(II)-pydim complex interface layer. The Ru(II)-pydim interface was deposited by spin coating technique on a p-silicon substrate. The electrical and optoelectrical parameters of photodiode were analyzed via the current-voltage (I-V), capacitance/conductance-voltage (C/G-V) measurements under dark and different illumination power. The fabricated device has good electrical parameters such as the rectification ratio of 2.726 x 104, the ideality factor of 1.328, and barrier height of 0.805 eV under the dark condition. The current values of the device with Ru(II)-pydim interface at reverse bias were strongly dependent on the illumination intensities, confirming its photoconduction behavior. The I-V measurements under different solar illuminations present that the electro-optic device with Ru(II)-pydim complex as an interface has good photodiode parameters with the responsivity of 131 mA/W, and the detectivity of 1.63 x 1011 Jones at 100 mW/cm2. The photo transient measurements demonstrate that the Ru(II)-pydim complex based photodiode presents the desired photo-switching property. Therefore, the prepared Ru(II)-pydim based device can be used for electro-optic and photonic applications, particularly in the rapidly developing organic material-based device industry.
Photoresponsivity and Photodetectivity Properties of Copper Complex-Based Photodiode
(Elsevier, 2020) Dayan, Osman; Imer, Arife Gencer; Al-Sehemi, Abdullah G.; Ozdemir, Namik; Dere, A.; Serbetci, Z.; Yakuphanoglu, F.
Spin coated Cu(II) complex thin layer onto p-Si substrate was used in photodiode fabrication. The structural properties of novel synthesized Cu(II) complex were investigated using different techniques. The single crystal X-ray diffraction (sc-XRD) technique confirms the Cu(II) complex containing 2-mesityl1H-benzo[d]imidazole ligands and two chloride ligands have a highly distorted cis-square-planar geometry. The thermogravimetric analysis (TGA) shows that the Cu(II) complex is stable up to 248 degrees C. Also, the current-voltage measurements were performed to investigate the characteristic of photodiode based on copper complex in darkness and under solar simulator. The fundamental electrical parameters of fabricated diode were obtained using Thermionic theory and modified Norde function. The manufactured device exhibits a good response to light with the defined rise and fall time of 351 ms and 622 ms under 100 mWcm(-2) solar illumination, respectively. Furthermore, frequency dependent capacitance and conductance measurements were performed in dark and under illumination. The obtained results suggest that prepared photodiode based on Cu(II) complex could be used for organic light detection in different optoelectronic applications as photodetector, photocapacitor, and photoconductor. (C) 2019 Elsevier B.V. All rights reserved.