Browsing by Author "Kucur, Banu"

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Determination of carrier concentrations in P-GaSb/n-InGaAsSb type II misaligned heterojunctions by the conductivity-magnetic field dependence
(Amer Scientific Publishers, 2013-01) Ahmetoğlu, Muhitdin A.; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Anabilim Dalı.; 16021109400; 36903670200
We present results in studying narrow-gap misaligned heterojunctions based on InxGa1-x,AsySb1-y/GaSb solid solutions with a composition close to In As (x >= 0.80, E-g = 0.26 eV at T = 300 K). Unusual asymmetric electrical properties of the heterostructures (N-n, P-p, N-p and P-n) as well as their energy band diagrams are discussed. The ohmic behaviour of P-GaSb/n-InGaAsSb structure and diode-like I-V characteristics of the N-p, N-n and P-p junctions have been observed in the temperature region from 4.2 K up to 300 K. Concentration of the P-n structure with ohmic behavior was determined by the conductivity-magnetic field dependence.
The determination of series resistance and interface state density distributions of Au/p-type GaAs Schottky barrier diodes
(Natl Inst Optoelectronics, 2013) Özer, Metin; Güzel, Tamer; Asimov, A.; Ahmetoglu, Muhitdin; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Anabilim Dalı.; 55849632800; 55849025200; 36903670200
The electronic and interface state density distribution properties obtained from current voltage (I-V) and capacitance-voltage (C-V) characteristics of Au/p-type GaAs Schottky barrier diode (SBD) at room temperature was investigated. The (I-V)-T characteristics are analysed on the basis of thermionic emission (TE). The forward bias I-V of SBDs have been studied at room temperature. SBD parameters such as ideality factor n, series resistance (Rs) determined by Cheung's functions and Schottky barrier height, Phi(bo), are investigated as functions of temperature. The diode parameters such as ideality factor, series resistance and barrier heights were found as 1.76-2.16 and 2.2-1.8 Omega and 0.53-0.72 eV, respectively. The diode shows non-ideal I-V behaviour with an ideality factor greater than unity. Furthermore, the energy distribution of interface state density was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. The results show the presence of thin interfacial layer between the metal and semiconductor.
Electrical and optical properties of the GaInAsSb-based heterojunctions for infrared photodiode and thermophotovoltaic cell application
(Elsevier, 2010-09) Andreev, Igor A.; Kunitsyna, Ekaterina V.; Mikhaǐlova, Maya P.; Yakovlev, Yu P.; Ahmetoğlu, Muhitdin A.; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 16021109400; 36903670200
The electrical end optical characteristics of a type II double heterojunction (DH) in the GaSb/GaInAsSb/GaAlAsSb system with staggered band alignment were studied. An analysis of the photodiodes performance through the investigation into electrical and optical characteristics was carried out. The dark current mechanisms in the heterostructures were investigated at several temperatures. The experimental results show that at the low temperature region, the tunneling mechanism of the current flow dominates in both forward and reverse biases. At high temperatures region and in the range of voltage from 0.1 V to 1 V, the reverse current was defined by generation of carriers in the depletion region. Have been estimated the temperature coefficient of the shift of the long-wavelength edge of the spectral sensitivity at half-maximum as Delta lambda/Delta T = 1.6 nm/K. Quantum efficiency of 0.6-0.7 for the investigated photodiodes was reached without any antireflection coating. For GaSb/GaInAsSb/GaAlAsSb TPV cells, the internal quantum efficiency of 90% was achieved at wavelengths between 1.2 and 1.6 mu m. (C) 2010 Elsevier B.V. All rights reserved.
Electrical characteristics and temperature dependence of photovoltaic parameters of GaInAsSb based TPV diode
(Polish Acad Sciences Inst Physics, 2016-04) Andreev, Iereus Alexey; Kunitsyna, Ekaterina V.; Mikhailova, Maya P.; Yakovlev, Yury P.; Kucur, Banu; Ahmetoğlu, Muhitdin; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; CZA-5782-2022; CCC-9142-2022; 36903670200; 16021109400
In this paper, electrical characterization of low bandgap GaInAsSb based thermophotovoltaic (TPV) diodes were investigated, as well as the temperature dependence of photovoltaic parameters such as short circuit current (I-sc) and open circuit voltage (V-oc). Investigation of the dark current mechanisms of the structure was carried out at several temperatures. The effect of light intensity on current-voltage characteristics was also investigated.
Electrical characteristics of Al/n-type GaAs Schottky barrier diodes at room temperature
(Natl Inst Optoelectronics, 2014-03) Asimov, Ahmed; Ahmetoğlu, Muhitdin A.; Kucur, Banu; Gücüyener, İsmet; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; 0000-0003-0783-4609; A-4861-2018; 55849632800; 16021109400; 36903670200; 15834767100
The current voltage (I-V) characteristics of metal semiconductor Al/n-GaAs (MS) Schottky diodes were measured at room temperature (300 K). In addition, capacitance-voltage-frequency (C-V-f) characteristics are investigated by considering the interface states (Nss) at frequency 1 MHz. SBD parameters such as ideality factor n, the series resistance (R-s) determined from Cheung's functions and Schottky barrier height, (phi(bo), are investigated as functions of temperature. Ideality factor, barrier height and series resistance values were found as 2.93-3.51, 0.58-1.47 eV and 0.80-0,59 Omega, respectively. The diode shows non-ideal I-V behaviour with an ideality factor greater than unity. Furthermore, the energy distribution of interface state density was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. The results show the presence of thin interfacial layer between the metal and semiconductor. The interface distribution profile (Nss) as a function of (E-c-E-ss) was extracted from the forward-bias I-V measurements by taking into account the bias dependence of the effective barrier height and series resistance (Rs) for the Schottky diodes. The value of N-SS obtained 1.92x10(13)(eV)(-1)cm(-2).
The electrical characterization of electrodeposited Ni thin film on silicon: Schottky barrier diodes
(Natl Inst Optoelectronics, 2012) Tekgül, Atakan; Ahmetoğlu, Muhitdin; Alper, Mürsel; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; AAG-8795-2021; 16021109400; 7005719283; 36903670200
A Ni/n-Si Schottky barrier diode was produced by electrodeposition technique from the electrolyte containing nickel ions under galvanostatic control. The deposition was carried out in a three-electrode cell at room temperature. The electrical characteristics of the Schottky diodes have been investigated using current-voltage (l-V) and capacitance-voltage (C-V) measurements. Ni/n-Si/AuSb diode current-voltage characteristics display low reverse bias leakage currents. The barrier height and ideality factor (n) were obtained 0.60 eV and 3.28 respectively. The high ideality factor value was attributed to oxide layer at the metal semiconductor interface.
The electrical properties of Au/MEH-PPV:PCBM/n-type GaAs Schottky barrier diode
(National Institute of Optoelectronics, 2016-11-25) Ahmetoglu (Afrailov), Muhitdin; Kırsoy, Ahmet; Asimov, A.; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; CBY-1915-2022; CCC-9142-2022; FDX-3050-2022; CZA-5782-2022; 55849025200; 56716481600; 55849632800; 36903670200
We fabricated the Au/Meh-PPV:PCBM/n-type GaAs Schottky barrier diodes (SBDs). Then we investigated Current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the diode at room temperature. MEH-PPV:PCBM (in a mass ratio 1:4) used as interfacial layer between metal and semiconductor layers. Here, MEH-PPV is poly [2-methoxy-5-(ethylhexyloxy)1,4-phenylenevinylene] and PCBM is [6,6]-phenyl-61C-butric acid methyl ester). SBD parameters such as ideality factor, barrier height and series resistance were obtained from I-V and C-V measurements. Also, Cheung functions and Norde Method were used to evaluate the I-V characteristics and to determine the characteristic parameters of the Schottky diode. The diode parameters such as ideality factor, barrier heights and series resistance were found as 4.39-4.54 and 0.57-0.63 eV and 51-53 Omega respectively. Also the interface states energy distribution of the diode was determined and found as 1.09 x 10(12) ev(-1)cm(-2)at (Ec-0.352) eV to 2.94 x 10(11) eV(-1)crn(-2) at (Ec-0.436) eV.
Electrical properties of GaAs-GaAlAs near infrared light emitting diodes
(Natl Inst Optoelectronics, 2012) Ahmetoğlu, Muhitdin; Kucur, Banu; Gücüyener, İsmet; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu/Mekatronik Programı Bölümü.; 16021109400; 36903670200; 15834767100
The electrical properties have been studied for GaAs/AlxGa1-xAs based infrared light emitting diode. The characteristics of the device have been analyzed and unusual feature of the device was observed. It operates as avalanche photodiode when it is reverse biased, while it operates as light emitting diode (LED) when it is forward biased.
Electrical properties of GaInAsSb/GaSb/GaAlAsSb Double Heterostructure with low diameter
(Polish Acad Sciences Inst Physics, 2014-02) Andreev, Igor A.; Kunitsyna, Ekaterina V.; Mikhaǐlova, Maya P.; Yakovlev, Yu P.; Kucur, Banu; Ahmetoğlu, Muhitdin A.; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 36903670200; 16021109400
GaInAsSb/GaSb/GaAlAsSb double heterostructures are attractive for optoelectronic devices working in the 1.5-4.8,mu m wavelength region. In this paper, the current mechanisms of liquid phase epitaxy grown GaInAsSb based double heterostructures with 100,mu m diameter were investigated in the temperature range 77-350 K. It was found that diffusion current dominates at the high temperature (> 240 K) and small forward bias region, while generation-recombination current dominates at intermediate temperatures (242-171 K). At low temperature region (< 171 K), the tunneling mechanism of the current flow dominates in both forward and reverse biases.
GaSb yarı iletken temelindeki infrared fotodiyotların karanlık akımlarının incelenmesi
(Uludağ Üniversitesi, 2011) Kucur, Banu; Ahmetoğlu, Muhitdin; Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/Fizik Anabilim Dalı.
Yarıiletken malzemeler ve bu malzemelerden üretilen doğrultucu, laser, transistör, ışık yayan diyot (LED), fotodetektör gibi araç ve gereçler, elektronik, bilgisayar teknolojisi, nanoteknoloji, askeri savunma sanayi, optik iletişim sistemleri gibi pek çok alanda yaygın olarak kullanılmaktadır. Son yıllarda, kızılötesi (infrared) bölgede çalışan yüksek verimli ışık kaynakları ve fotoalıcılar, ayrıca bunların imal edilmesi için gereken yarıiletken malzemelerin incelenmesi güncel bir konu haline gelmiştir. Söz konusu spektrum bölgesinde çalışan optoelektronik düzeneklerin imal edilmesi için GaSb ve InAs gibi taban malzemeler ile örgü sabitleri uyumlu olan GaInAsSb, GaAlAsSb, InAsSbP gibi dört bileşenli katı çözeltiler uygun malzemeler olarak görülmektedirler.Bu çalışmada kızılötesi bölgede çalışan GaSb/GaInAsSb/GaAlAsSb çift heteroyapı numunesinin elektrik özellikleri incelenmiştir. C-V ve I-V ölçümlerinin yanı sıra hesaplanan ideal faktör ve aktivasyon enerjisi değerlerinden de faydalanılarak farklı sıcaklıklardaki karanlık akım mekanizmaları yorumlanmıştır.
Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/ carbon nanotube, single-walled)/n-GaAs Diode Formed by Surface Polymerization
(Polish Acad Sciences Inst Physics, 2016-07) Ahmetoğlu, Muhitdin A.; Kara, Ali; Kucur, Banu; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü.; 0000-0003-2457-6314; AAG-6271-2019; 16021109400; 7102824859; 36903670200
Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/carbon nanotube, single-walled)/n-GaAs ([P(EGDMA-VTAZ)-CNSW]/n-GaAs) diode was fabricated by using surface polymerization method. Electrical properties were carried out at several temperatures. Dark current mechanisms were investigated by using current-voltage (I-V) measurements. It was shown that the fabricated structure exhibited rectification behaviour that makes it a good candidate for electronic device applications.