Yazar "Ardalı, Şükrü" için listeleme
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Acceptor formation in Mg-doped, indium-rich GaxIn1-xN: evidence for p-type conductivity
Balkan, Naci; Tıraş, Engin; Erol, Ayşe; Güneş, Mustafa; Ardalı, Şükrü; Arıkan, Çetin; Gümüş, Cebrail (Springer, 2012)We report on the Mg-doped, indium-rich Ga (x) In1-x N (x < 30). In the undoped material, the intrinsic electron density is very high and as a result there is no detectable photoconductivity (PC) signal within the range of ... -
Classical and quantum hall effect measurements in GaInNAs/GaAs quantum wells
Ardalı, Şükrü; Tıraş, Engin (Elsevier Science BV, 2013)We have performed magneto-transport experiments in modulation-doped Ga0.7In0.3NyAs1-y/GaAs quantum wells with nitrogen mole fractions 0.4%, 1.0% and 1.5%. Classical magnetotransport (resistivity and low-field Hall effect) ... -
Complementary and alternative technique for the determination of electron effective mass: quantum Hall effect
Ardalı, Şükrü; Tıraş, Engin; Arslan, E.; Özbay E. (Natl Inst Optoelectronics, 2016)The quantum Hall effect measurements in the AlInN/AlN/GaN heterostructure are studied in the temperature range from 1.8 K to 14 K and a magnetic field up to 11 T. The quantized two-dimensional electron gas was placed at ... -
Contactless electron effective mass determination in GaInNAs/GaAs quantum wells
Tıraş, Engin; Ardalı, Şükrü (Springer, 2013)The electron effective masses in n-type modulation doped Ga0.7In0.3NyAs1-y/GaAs quantum wells with nitrogen mole fractions of y = 0.004 and 0.010 were investigated experimentally. Two experimental techniques: magnetic field ... -
Determination of dislocation densities in InN
Ardalı, Şükrü; Tıraş, Engin; Güneş, Mustafa; Balkan, Naci; Ajagunna, Adebowale Olufunso; Iliopoulos, Eleftherios; Georgakilas, Alexandros (Wiley-V C H Verlag GMBH, 2012)The magneto-transport measurements, carried out at magnetic fields up to 11 T and in the temperature range between 1.8 K and 300 K, are used to investigate the scattering mechanisms in GaN/InN/AlN double heterojunctions. ... -
Determination of the carrier density dependent electron effective mass in InN using infrared and Raman spectra
Tıraş, Engin; Tanışlı, Murat; Balkan, Naci; Ardalı, Şükrü; Iliopoulos, E.; Georgakilas, A. (Wiley-V C H Verlag GMBH, 2012)The vibrational properties of InN samples grown by molecular beam epitaxy (MBE) technique have been studied using infrared (IR) and Raman scattering spectroscopy at room temperature. In the Raman measurements, the 532?nm ... -
Determination of the in-plane effective mass and quantum lifetime of 2D electrons in AlGaN/GaN based HEMTs
Çelik, Özlem; Tıraş, Engin; Ardalı, Şükrü; Lisesivdin, Sefer Bora; Özbay Ekmel (Wiley-V C H Verlag GMBH, 2011)Magnetoresistance and Hall resistance measurements have been used to investigate the electronic transport properties of AlGaN/GaN based HEMTs. The Shubnikov-de Haas (SdH) oscillations from magnetoresistance, is obtained ... -
Determination of the LO phonon energy by using electronic and optical methods in AlGaN/GaN
Çelik, Özlem; Tıraş, Engin; Ardalı, Şükrü; Lisesivdin, Sefer Bora; Özbay Ekmel (De Gruyter Open LTD, 2012)The longitudinal optical (LO) phonon energy in AlGaN/GaN heterostructures is determined from temperature-dependent Hall effect measurements and also from Infrared (IR) spectroscopy and Raman spectroscopy. The Hall effect ... -
Effective mass of electron in monolayer graphene: Electron-phonon interaction
Tıraş, Engin; Ardalı, Şükrü; Tıraş, T.; Arslan, E.; Cakmakyapan, S.; Kazar, O.; Özbay E. (Amer Inst Physics, 2013)Shubnikov-de Haas (SdH) and Hall effect measurements performed in a temperature range between 1.8 and 275 K, at an electric field up to 35 kV m(-1) and magnetic fields up to 11 T, have been used to investigate the electronic ... -
Electron and hole energy relaxation rates in GaInNAs/GaAs quantum wells via deformation potential and piezoelectric scattering
Tıraş, Engin; Ardalı, Şükrü (Wiley-V C H Verlag GMBH, 2013)The two-dimensional (2D) electron and hole energy relaxation associated with acoustic phonon emission in n- and p-type modulation doped Ga0.7In0.3NyAs1y/GaAs quantum wells has been investigated experimentally using ... -
Energy relaxation of hot electrons by LO phonon emission in AlGaN/AlN/GaN heterostructure with in situ Si3N4 passivation
Atmaca, G.; Ardalı, Şükrü; Narin, P.; Kutlu, E.; Lisesivdin, Sefer Bora; Malin, T.; Tıraş, Engin (Elsevier Science Sa, 2016)In this study, energy relaxation mechanisms of electrons in AlGaN/AlN/GaN High Electron Mobility Transistor (HEMT) structures with and without in situ Si3N4 passivation were investigated. Although the physical parameters ... -
Energy Relaxation Rates in AlInN/AlN/GaN Heterostructures
Tıraş, Engin; Ardalı, Şükrü; Arslan, E.; Özbay E. (Springer, 2012)The two-dimensional (2D) electron energy relaxation in Al0.83In0.17N/AlN/GaN heterostructures has been investigated experimentally. Shubnikov-de Haas (SdH) effect measurements were employed in the investigations. The ... -
Grafen yapılarda SdH yöntemi ile güç kaybı mekanizmalarının incelenmesi
Ardalı, Şükrü (Anadolu Üniversitesi, 2017)Bu doktora tez çalışmasında SiO2/Si ve SiC alttaşlar üzerine büyütülmüş tek katman grafen örneklerin galvonomagnetik ölçümleri yapıldı. Düşük magnetik alan değerlerinde yapılan klasik Hall olayı ölçümleri sabit magnetik ... -
InN ve GaInN örneklerde galvanomagnetik ölçümler
Ardalı, Şükrü (Anadolu Üniversitesi, 2010)Bu tezde InN ve Ga1-xInxN örneklerde galvonomagnetik ölçümler yapıldı. Deneylerde üç farklı örnek grubu kullanıldı. Örnekler Molecular Beam Epitaxy (MBE) büyütme sistemi ile Cornell Üniversitesi (Amerika Birleşik Devletleri) ... -
Longitudinal polar optical phonons in InN/GaN single and double heterostructures
Ardalı, Şükrü; Tıraş, Engin; Güneş, Mustafa; Balkan, Naci; Ajagunna, Adebowale Olufunso; Iliopoulos, Eleftherios; Georgakilas, Alexandros (Wiley-V C H Verlag GMBH, 2011)Longitudinal optical phonon energy in InN epi-layers has been determined independently from the Raman spectroscopy and temperature dependent Hall mobility measurements. Raman spectroscopy technique can be used to obtain ... -
Power-loss mechanisms in surface passivated AlGaN/AlN/GaN heterojunctions
Tıraş, Engin; Atmaca, G.; Lisesivdin, S. B.; Ardalı, Şükrü; Malin, T.; Mansurov, V.; Zhuravlev, K. (Institute of Electrical and Electronics Engineers Inc., 2016)The surface passivation effect on the power-loss mechanisms in AlGaN/AlN/GaN heterostructures was investigated. The electron temperatures of hot electrons was obtained from the temperature and the applied electric field ... -
Quantum lifetimes and momentum relaxation of electrons and holes in Ga0.7In0.3N0.015As0.985/GaAs quantum wells
Tıraş, Engin; Balkan, Naci; Ardalı, Şükrü; Güneş, M.; Fontaine, C.; Arnoult, A. (Taylor & Francis LTD, 2011)Electronic transport in n-and p-type modulation-doped Ga0.7In0.3N0.015As0.985/GaAs quantum wells are investigated using magneto-transport measurements in the temperature range between T = 1.8 and 32K and at magnetic fields ... -
Scattering analysis of 2DEG mobility in undoped and doped AlGaN/AlN/GaN heterostructures with an in situ Si3N4 passivation layer
Atmaca, G.; Ardalı, Şükrü; Tıraş, Engin; Malin, T.; Mansurov, V. G.; Zhuravlev, K. S.; Lisesivdin, S. B. (Pergamon-Elsevier Science LTD, 2016)The scattering mechanisms limiting mobility for low-dimensional charge carriers in a two-dimensional electron gas (2DEG) in undoped and doped AlGaN/AlN/GaN heterostructures with and without Si3N4 passivation are investigated. ... -
Superconductivity in MBE grown InN
Güneş, M.; Balkan, Naci; Tıraş, Engin; Ardalı, Şükrü; Ajagunna, Adebowale Olufunso; Iliopoulos, Eleftherios; Georgakilas, A. (Wiley-V C H Verlag GMBH, 2011)We present the experimental investigation of superconductivity in unintentionally doped MBE grown InN samples with various InN film thicknesses. A significant change in resistivity was observed at 3.82K, for an 1080 nm InN ... -
Temperature and magnetic field effect on oscillations observed in GaInNAs/GaAs multiple quantum wells structures
Khalil, H. M.; Mazzucato, S.; Ardalı, Şükrü; Çelik, O.; Mutlu, S.; Royall, B.; Guina, M. (Elsevier Science BV, 2012)The photoconductivity of p-i-n GaInNAs/GaAs multiple quantum well (MQW) mesa structures is investigated. When illuminated with photons at energy greater than the GaAs bandgap, a number of oscillations are observed in the ...
