Yazar "Asubay, S." seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Current-voltage and capacitance-voltage characteristics of Fe/p-InP Schottky barriers(Taylor & Francis Ltd, 2010) Asubay, S.; Gullu, O.The electrical properties of identically prepared Fe/p-InP (29 dots in total) Schottky barrier diodes on the same p-type InP single crystal have been studied in this article. The effective Schottky barrier heights (SBHs) and ideality factors obtained from current-voltage (I-V) characteristics differ from diode to diode. The SBHs and the ideality factors for the Fe/p-InP diodes ranged from 0.71 to 0.86eV and 1.21 to 1.69, respectively. A lateral homogeneous SBH value of 0.91eV for the Fe/p-InP diodes has been calculated from the linear relationship between barrier heights and ideality factors, which can be explained by lateral inhomogeneities of the SBHs.Öğe Determination of the laterally homogeneous barrier height of metal/p-InP Schottky barrier diodes(Pergamon-Elsevier Science Ltd, 2009) Asubay, S.; Gullu, O.; Turut, A.We have reported a study of a number of metal/p-type InP (Cu, Au, Al, Sn, Pb, Ti, Zn) Schottky barrier diodes (SBDs). Each one diode has been identically prepared on p-InP under vacuum conditions with metal deposition. In Schottky diodes, the current transport occurs by thermionic emission over the Schottky barrier. The current-voltage characteristics of Schottky contacts are described by two fitting parameters such as effective barrier height and the ideality factor. Due to lateral inhomogeneities of the barrier height, both characteristic diode parameters differ from one diode to another. We have determined the lateral homogeneous barrier height of the SBDs from the linear relationship between experimental barrier heights and ideality factors that can be explained by lateral inhomogeneity of the barrier height. Furthermore, the barrier heights of metal-semiconductor contacts have been explained by the continuum of metal-induced gap states (MIGS). It has been seen that the laterally homogeneous barrier heights obtained from the experimental data of the metal/p-type InP Schottky contacts quantitatively confirm the predictions of the combination of the physical MIGS and the chemical electronegativity. (C) 2009 Elsevier Ltd. All rights reserved.Öğe Determination of the laterally homogeneous barrier height of thermally annealed and unannealed Au/p-InP/Zn-Au Schottky barrier diodes(Elsevier, 2008) Asubay, S.; Gullu, O.; Turut, A.We have identically prepared Au/p-InP Schottky barrier diodes (SBDs). The diodes were annealed up to 400 degrees C thermally. The barrier height (BH) for the as-deposited Au/p-InP/Zn-Au SBDs from the current-voltage characteristics have varied from 0.58 to 0.72 eV, and ideality factor n from 1.14 to 1.47. The BH for the annealed SBDs from the current-voltage characteristics have varied from 0.76 to 0.82 eV, and ideality factor n from 1.17 to 1.39. As a result of the thermal annealing, it has been seen that the BH values of the annealed SBDs are larger than those of the as-deposited SBDs. We have determined a lateral homogeneous BH value of 0.72 eV for the as-deposited Au/p-InP SBD from the experimental linear relationship between barrier heights and ideality factors, and a value of 0.85 eV for the annealed Au/p-InP SBD. The increase of 0.13 eV in the BH value by means of 400 degrees C annealing has been ascribed to the formation of the excess charges that electrically actives on the semiconductor surface. (C) 2007 Elsevier B.V. All rights reserved.Öğe Electrical characterization of organic-on-inorganic semiconductor Schottky structures(Iop Publishing Ltd, 2008) Guellue, Oe; Tueruet, A.; Asubay, S.We prepared a methyl red/p-InP organic-inorganic (OI) Schottky device formed by evaporation of an organic compound solution directly to a p-InP semiconductor wafer. The value of the optical band gap energy of the methyl red organic film on a glass substrate was obtained as 2.0 eV. It was seen that the Al/methyl red/p-InP contacts showed a good rectifying behavior. An ideality factor of 2.02 and a barrier height (Phi(b)) of 1.11 eV for the Al/methyl red/p-InP contact were determined from the forward bias I-V characteristics. It was seen that the value of 1.11 eV obtained for Phi(b) for the Al/methyl red/p-InP contact was significantly larger than the value of 0.83 eV for conventional Al/p-InP Schottky diodes. Modification of the interfacial potential barrier for the Al/p-InP diode was achieved using a thin interlayer of the methyl red organic semiconductor. This ascribed to the fact that the methyl red interlayer increases the effective Phi(b) by influencing the space charge region of InP.Öğe Electrical characterization of the Al/new fuchsin/n-Si organic-modified device(Elsevier, 2010) Gullu, O.; Asubay, S.; Aydogan, S.; Turut, A.The current-voltage (I-V) and the capacitance-voltage (C-V) characteristics of the Al/new fuchsin (NF)/n-Si device have been investigated at room temperature. The I-V characteristic of the device shows a good rectification. The ideality factor and the barrier height from the I-V characteristics have been determined as 3.14 and 0.80 eV, respectively. A modified Norde's function combined with the conventional I-V method has been used to extract the parameters including the barrier height and the series resistance. The barrier height and the series resistance obtained from Norde's function have been compared with those from Cheung functions, and it has been seen that there was a good agreement between those from both method. It has also been seen that the values of diode capacitance increased up to the constant values for the forward bias. (C) 2009 Elsevier B.V. All rights reserved.Öğe Electrical properties of safranine T/p-Si organic/inorganic semiconductor devices(Edp Sciences S A, 2010) Gullu, O.; Asubay, S.; Biber, M.; Kilicoglu, T.; Turut, A.We investigated the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of identically prepared safranine T/p-Si organic/inorganic Schottky devices (total 26 diodes) formed by evaporation of organic compound solution on p-Si semiconductor substrate. It was seen that the safranine T organic thin film on the p-Si substrate showed a good rectifying behavior. The barrier heights and ideality factors of all devices were extracted from the electrical characteristics. The mean barrier height and mean ideality factor from I-V measurements were calculated as 0.59 +/- 0.02 eV and 1.80 +/- 0.20, respectively. Also, the mean barrier height and mean acceptor doping concentration from C-V measurements were calculated as 0.67 +/- 0.10 eV and (6.96 +/- 0.37) x10(14) cm(-3), respectively. The discrepancy in the barrier height values obtained from I-V and C-V characteristics has been attributed to different nature of the measurements. The discrepancy between these values can also be due to the existence of the interfacial native oxide and the organic safranine T thin layer between the semiconductor substrate and top contact metal.Öğe Morphological and electrical properties of Ag/p-type indium phosphide MIS structures with malachite green organic dyes(Virtual Co Physics Srl, 2022) Asubay, S.; Ava, C. A.; Gullu, O.Malachite Green (MG) organic dye thin film was prepared by simple drop casting method. Microstructural property of MG layer was investigated by Scanning Electron Microscopy (SEM). SEM image indicated that MG organic thin layer was formed from nanoclusters. Later, it was fabricated Ag/Malachite Green(MG)/p-InP diodes by drop cast method. The barrier height (BH) and ideality factor by using I-V characteristics for the device were found as 0.75 eV and 1.68. By using the Norde method, the BH and the resistance of neutral region of the device were extracted as 0.80 eV and 1.17x104 ??. The interfacial states concentration of the device has been seen to decrease from 2.79??1013 eV-1cm-2 to 5.80??1012 eV-1cm-2. By using capacitance-voltage technique, the values of the built-in voltage, BH and semiconductor doping density were found as 1.22 V, 0.83 eV and 1.87x1017 cm-3 for the Ag/MG/p-InP diode, respectively.Öğe Production of PbO thin film using Silar method and electronic and interface properties of Pb/PbO/p-Si MIS contacts(Virtual Co Physics Srl., 2022) Erdem, E.; Asubay, S.; Güllü, O.In this paper, using SILAR thin film technique, which is low cost and is easy to control, the lead oxide (PbO) thin film was grown onto both microscope glass and inorganic semiconductor silicon (Si) wafer after appropriate chemical cleaning processes. The coating stage was performed by keeping the solution at 80 celcius. After forming a PbO thin film on the silicon semiconductor, Pb metal was evaporated onto its upper surface. Optical, morphological and structural properties of the PbO thin film formed on glass were investigated. The electrical and interface characteristics of the Pb/PbO/p-Si MIS Schottky diode were investigated in the dark by using current-voltage (I-V), capacity-voltage (C-V) and conductance-voltage (G-V) in 10kHz-2MHz frequency range and capacity-frequency (C-f) characteristics in 1kHz-10MHz frequency range.Öğe REACTIVELY SPUTTERED MoO3 THIN FILMS AND TEMPERATURE DEPENDENCE OF ELECTRICAL PROPERTIES OF AN Ag/MoO3/n-Si DIODE(Natl Inst R&D Materials Physics, 2018) Cebisli, G.; Asubay, S.; Ocak, Y. S.MoO3 thin films were deposited onto n-Si and soda lime glass substrates by the reactive sputtering method. The influence of reactive gas flows on the morphological, structural and optical properties of thin films were analyzed by Atomic Force Microscopy (AFM), X-ray Diffraction (XRD) system and UV-Vis data. It was seen that the homogeneity and amorphousness of the films increase with the O-2 ratio. In addition, the Ag/MoO3/n-Si structure was obtained by evaporation of Ag on MoO3/n-Si structure. It was seen that the device had excellent rectification. The electrical properties of Ag/MoO3/n-Si structure were analyzed by current-voltage (I-V) measurements in the dark between 77 and 500 K. It was reported that the temperature had a strong influence on the electrical parameters of the device.
