Yazar "Ergün, Yüksel" için Fizik Bölümü listeleme
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Barrier lowering effect and dark current characteristics in asymmetric GaAs/AlGaAs multi quantum well structure
Altın, E.; Hoştut, Mustafa; Ergün, Yüksel (Springer, 2011)In this study, we investigate dark current voltage characteristics of GaAs/AlGaAs staircase-like asymmetric multiquantum well structure at various temperatures experimentally. The activation energy is calculated by using ... -
Broadband staircase quantum well infrared photodetector with low dark current
Ergün, Yüksel; Hoştut, Mustafa; Eker, Süleyman Umut; Sökmen, İsmail (Elsevier Science BV, 2006)We present a theoretical investigation of a novel staircase-like quantum well infrared photodetector (QWIP). It detects wavelengths between 8.8 mu m and 12.3 mu m at an applied electric field of F= 6 x 10(4) V/cm at room ... -
Broadband staircase quantum well infrared photodetector: working in long wavelength infrared range (LWIR)
Hoştut, Mustafa; Kartal, D.; Ergün, Yüksel; Sökmen, İsmail (Wiley-V C H Verlag GMBH, 2007)We present a theoretical investigation of a staircase-like quantum well infrared photodetector (QWIP). it detects wavelength between 7.6 mu m and 13.5 mu m range at an applied electric field of F = 1.9x10(4) V/cm at 77 K. ... -
Comprehensive growth and characterization study on highly n-doped InGaAs as a contact layer for quantum cascade laser applications
Demir, İlkay; Altuntaş, İsmail; Bulut, Barış; Ezzedini, Maher; Ergün, Yüksel; ElagÖz, Sezai (IOP Publishing LTD, 2018)We present growth and characterization studies of highly n-doped InGaAs epilayers on InP substrate by metal organic vapor phase epitaxy to use as an n-contact layer in quantum cascade laser applications. We have introduced ... -
Dark current and optical properties in asymmetric GaAs/AlGaAs staircase-like multiquantum well structure
Altın, E.; Hoştut, Mustafa; Ergün, Yüksel (Elsevier Science BV, 2013)In this study, we investigate dark current voltage characteristics of GaAs/AlGaAs staircase-like asymmetric multiquantum well structure at various temperatures experimentally. Measured dark current density voltage (J(d)-V) ... -
Effect of exchange-correlation potential on the plasmon dispersions in a doped symmetrical double quantum well
Tüzemen, E. Senadim; Türkoğlu, A.; Ergün, Yüksel; Sökmen, İsmail; Tanatar, B. (Wiley-V C H Verlag GMBH, 2007)We have calculated the plasmon dispersion relations in a doped double quantum well with and without exchange-correlation potential added to the effective potential of the system. The calculations were done for high and low ... -
Electrical and optical performance of InAs / AlSb / GaSb superlattice photodetector
Hoştut, M.; Tansel, Tunay; Ergün, Yüksel; Kılıç, A.; Aydınlı, A. (TANGER Ltd., 2015)We report on electrical and optical performance of InAs/AlSb/GaSb type-II superlattice photodetectors. The detector structure is designed to operate in the MWIR domain with a cut-off wavelength of 4.3 µm at 125 K. The ... -
Electrical and optical performances with extracted minority carrier lifetimes of InAs/GaSb SL photodetector operating in the mid wavelength infrared range
Tansel, Tunay; Hoştut, Mustafa; Ergün, Yüksel (Academic Press LTD- Elsevier Science LTD, 2017)We report a study on the temperature dependence of electrical and optical performance of InAs/GaSb based type-II superlattice (T2SL) pin photodetectors in the mid wavelength infrared range (MWIR). The SL structure exhibits ... -
Exciton states in a quantum dot with parabolic confinement
In this study the electronic eigenstructure of an exciton in a parabolic quantum dot (QD) has been calculated with a high accuracy by using Finite element method (FEM). We have converted the coordinates of electronlight-hole ... -
Ground state energy of excitons in quantum dot treated variationally via Hylleraas-like wavefunction
Şakiroğlu, S.; Doğan, Ue.; Yıldız, Aylin; Akgüngor, K.; Epik, H.; Ergün, Yüksel; Sökmen, I. (IOP Publishing LTD, 2009)In this work, the effects of quantum confinement on the ground state energy of a correlated electron-hole pair in a spherical and in a disc-like quantum dot have been investigated as a function of quantum dot size. Under ... -
High quantum efficiency Type-II superlattice N-structure photodetectors with thin intrinsic layers
Ergün, Yüksel; Hoştut, Mustafa; Tansel, Tunay; Muti, Abdullah; Kılıç, Abidin; Turan, Raşit; Aydınlı, Atilla (Spie-Int Soc Optical Engineering, 2013)We report on the development of InAs/AlSb/GaSb based N-structure superlattice pin photodiode. In this new design, AlSb layer in between InAs and GaSb layers acts as an electron barrier that pushes electron and hole wave ... -
I-V characterization of a staircase quantum well infrared photodetector
Nutku, Ferhat; Arıkan, M. Çetin; Erol, Ayşe; Ergün, Yüksel; Kendirlik, E. Metin (Wiley-V C H Verlag GMBH, 2011)In this work, a quantum well infrared photodetector structure which consists of three different well thicknesses with three different barrier compositions producing a staircase-like conduction band profile with the reputation ... -
Intersubband electron transition across a staircase potential containing quantum wells: light emission
Ergün, Yüksel; Hoştut, Mustafa; Eker, Süleyman Umut; Sökmen, İsmail (Academic Press LTD Elsevier Science LTD, 2005)We present a theoretical investigation of a novel staircase-like light emitter based on the GaAs/GaxAl1-xAs material system. The emission wavelength is around 12 mum. The device operation is based on the intersubband ... -
Low dark current N structure superlattice MWIR photodetectors
Salihoğlu, Ömer; Muti, Abdullah; Turan, Raşit; Ergün, Yüksel; Aydınlı, Atilla (Spie-Int Soc Optical Engineering, 2014)Commercially available read out integrated circuits (ROICs) require the FPA to have high dynamic resistance area product at zero bias (R(0)A) which is directly related to dark current of the detector. Dark current arises ... -
N structure for type-II superlattice photodetectors
Salihoğlu, Ömer; Muti, Abdullah; Kutluer, Kutlu; Tansel, Tunay; Turan, Raşit; Ergün, Yüksel; Aydınlı, Atilla (Amer Inst Physics, 2012)In the quest to raise the operating temperature and improve the detectivity of type II superlattice (T2SL) photodetectors, we introduce a design approach that we call the "N structure." N structure aims to improve absorption ... -
N-structure based on InAs/AlSb/GaSb superlattice photodetectors
Hoştut, M.; Alyörük, M.; Tansel, Tunay; Kılıç, A.; Turan, Raşit; Aydınlı, A.; Ergün, Yüksel (Academic Press LTD- Elsevier Science LTD, 2015)We have studied the theoretical and experimental properties of InAs/AlSb/GaSb based type-II superlattice (T2SL) pin photodetector called N-structure. Electronic properties of the superlattice such as HH-LH splitting energies ... -
A new approach to quantum well infrared photodetectors: Staircase-like quantum well and barriers
Eker, Süleyman Umut; Hoştut, Mustafa; Ergün, Yüksel; Sökmen, İsmail (Elsevier Science BV, 2006)We present a theoretical investigation of a novel staircase-like quantum well infrared photodetector (QWIP). The proposed structure makes use of quantum wells and barriers with increasing Al content both in the wells and ... -
A study of photomodulated reflectance on staircase-like, n-doped GaAs/Al (x) Ga1-x As quantum well structures
Dönmez, Ömer; Nutku, Ferhat; Erol, Ayşe; Arıkan, Çetin M.; Ergün, Yüksel (Springer, 2012)In this study, photomodulated reflectance (PR) technique was employed on two different quantum well infrared photodetector (QWIP) structures, which consist of n-doped GaAs quantum wells (QWs) between undoped Al (x) Ga1-x ... -
Three-color broadband asymmetric quantum well infrared photodetectors in long wavelength infrared range (LWIR)
Hoştut, Mustafa; Alyörük, M.; Ergün, Yüksel; Sökmen, İsmail (Springer, 2010)A theoretical investigation of a GaAs/AlGaAs-material-system-based four quantum well infrared detector structures consisting of ten periods of three asymmetric quantum well units are presented. Each quantum well in the ... -
Tunable long-wavelength broad band asymmetric quantum well infrared photodetector
Hoştut, Mustafa; Kartal, D.; Ergün, Yüksel; Sökmen, İsmail (IOP Publishing LTD, 2007)We present a theoretical investigation of a GaAs/AlGaAs infrared detector consisting of three asymmetric quantum wells. Each well is designed to yield absorption and a photoresponse at peak wavelengths of 8.2 mu m, 9.5 mu ...