Browsing by Author "Mikhaǐlova, Maya P."

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    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.
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    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.
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    Gallium antimonide - Based photodiodes and thermophotovoltaic devices
    (Amer Inst Physics, 2007) Andreev, Igor A.; Kunitsyna, Ekaterina V.; Mikhaǐlova, Maya P.; Yakovlev, Yu P.; Ahmetoğlu, Muhitdin A.; Ertürk, Kadir; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-9555-6903; ABA-5148-2020; 16021109400; 18036952100
    This paper briefly presents some important aspects of the GaSb-based material growth, as well as the performance of photodiodes and TPV devices for the 0.9-2.55 mu m spectral range. A reproducible technique has been developed for the production of high-speed and high-efficiency GaSb/GaInAsSb/GaAlAsSb photodiodes. The detectivity of the photodiodes, estimated from the measured noise level and monochromatic current sensitivity, in the spectral peak reaches D*(lambda(max), 1000,1)=(0.8-1.0)x10(11) W(-1)xcmxHz(1/2) at room temperature. Recently, we have adapted the technology for creating GaInAsSb (0.52-0.53 eV band gap) TPV devices. Based on the our results we believe a 0.5 eV band gap GaSb-based TPV cell with an open-circuit voltage well over 300 mV at current 2-3 A is a realistic near-term goal.
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    Narrow gap III-V materials for infrared photodiodes and thermophotovoltaic cells
    (Elsevier, 2010-10) Kunitsyna, Ekaterina V.; Andreev, Igor A.; Sherstnev, Victor V.; L'Vova, T. V.; Mikhaǐlova, Maya P.; Yakovlev, Yu P.; Ahmetoğlu, Muhitdin A.; Kaynak, Gökay; Gürler, Orhan; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; AAH-1837-2021; 16021109400; 12042075600; 14019444500
    The paper describes liquid phase epitaxial growth and characterization of the GaSb- and InAs-related materials for the photodiodes and thermophotovoltaic applications. It was shown that doping of the melt with holmium results in obtaining the high purity GaInAsSb and InAs layers. The passivation with the 1 M Na2S aqueous solution makes it possible to prepare flat growth surfaces of GaSb(1 0 0) and InAs(1 0 0) substrates after annealing. A reproducible technique has been developed for fabrication of the high-efficiency GaInAsSb/GaAlAsSb and InAs/InAsSbP photodiodes with the long-wavelength photosensitivity edge of 2.4 and 3.8 mu m, respectively. Room temperature detectivity in the spectral peak reaches D* = (0.8-1.0) x 10(11) W-1 cm Hz(1/2) for the GaInAsSb/GaAlAsSb photodiodes and D* = (3.0-5.0) x 109 W-1 cm Hz(1/2) for the InAs/InAsSbP devices. We have adapted the technology for thermophotovoltaic cells operating at an emitter temperature of 1000-1700 degrees