Browsing by Author "Kadirov, O."

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    Photoelectrical characteristic of isotype N+-GaSb/n(0)-GaInAsSb/N+-GaAlAsSb type II heterojunctions
    (Journal of Optoelectronics and Advanced Materials, 2008-10) Boydedayev, S. R.; Kadirov, O.; Ahmetoğlu, Muhitdin; Özer, Mehmet; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 16021109400; 9742545600
    Photoelectrical characteristics and energy diagrams have been studied for LPE grown isotype heterostructures lattice-matched to GaSb substrates. The photocurrent sign dependence on photon energy as a function of forward bias in isotype N+-GaSb/n(0)-GaInAsSb/N+-GaAIAsSb heterojunctions due to hole confinement at the type II interface is observed and discussed. This effect is due to modulation of the barrier transparency at the interface limiting the tunnel transitions of the conduction electrons and to the localization of photoholes in the potential well at the type II interface. The sign reversal of the photocurrent on photon energy as a function of applied voltage takes place only on the forward bias.
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    Photoelectrical properties of InP-InGaAsp heterojunction avalanche photodiodes
    (Natl Inst Optoelectronics, 2009-06) Kadirov, O.; Ahmetoğlu, Muhitdin; Özer, Mehmet; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 16021109400; 9742545600
    Photoelectrical properties and the spectrum of the avalanche multiplication factor versus the reverse voltage at room temperature have been studied for LPE grown for InP-In(x)Ga(1-x)AsyP(1-y) heterostructures. The tunneling current becomes substantial at peak junction electric fields as low as 10(5) V/m due to the small direct energy gaps and small effective masses of the structures tested. The process of breakdown in the investigated structures was of the avalanche type. The results found for the lowering of the tunneling current in the pre-breakdown region. The temperature coefficient of the breakdown voltage beta = (1/V-B).(dV(B)/dT) > 0 was determined in the temperature range 77-300 K and its value was found to be beta = 5.78 x 10(-4) K-1.