Browsing Nanoteknoloji Mühendisliği Bölümü Makale Koleksiyonu by Author "0000-0002-3979-7868"
Now showing items 1-13 of 13
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Arsine Flow Rate Effect on the Low Growth Rate Epitaxial InGaAs Layers
Altuntaş, İsmail (07.06.2021)Effect of arsine (AsH3) flow rate on epitaxially grown unintentionally doped and low-growth rate InGaAs layer by using metal organic vapor phase epitaxy at growth temperature 640°C are investigated. While all other sources ... -
Combined effects of electric, magnetic, and intense terahertz laser fields on the nonlinear optical properties in GaAs/GaAlAs quantum well with exponentially confinement potential
Altuntas, İsmail; Dakhlaoui, H.; Mora-Ramos, M. E.; Ungan, Fatih (15.11.2021)We are presenting a theoretical investigation on the effects of applied electric, magnetic, and non-resonant intense laser field on the coefficients of intersubband linear, third-order nonlinear, and total optical ... -
Determination of Optical Properties of MOVPE‑Grown InxGa1‑xAs/ InP Epitaxial Structures by Spectroscopic Ellipsometry
Emine Kaynar; Muhammed Sayraç; İsmail Altuntaş; İlkay Demir (24.08.2022)InxGa1−xAs epitaxial layers with different AsH3 flows have been grown on InP substrate with the MOVPE system. It has been found that AsH3 flow variation affects the In concentration of InGaAs/InP structure because the ... -
Effects of applied external fields on the nonlinear optical rectification, second, and third harmonic generation in a quantum well with exponentially confinement potential
Altuntaş, İsmail (6.11.2021)In the present study, the nonlinear optical rectification (NOR), second harmonic generation (SHG), and third harmonic generation (THG) coefficients in GaAs/GaAlAs quantum well (QW) with exponentially confinement potential ... -
Growth and characterization of PALE Si-doped AlN on sapphire substrate by MOVPE
Kağan Murat Pürlü; Merve Nur Koçak; Gamze Yolcu; İzel Pertikel; İsmail Altuntaş; İlkay Demir (16.01.2022)teristics of heteroepitaxial Metal-Organic Vapor Phase Epitaxy (MOVPE) grown AlN layers on sapphire substrates. Adjustment of growth kinetics is very important to control the doping. Therefore, pulsed atomic layer epitaxy ... -
In-situ and ex-situ face-to-face annealing of epitaxial AlN
Merve Nur Koçak; Kağan Murat Pürlü; İzel Pertikel; İsmail Altuntaş; İlkay Demir (26.06.2022)AlN films have been deposited on c-plane sapphire substrates by metalorganic-vapor-phase-epitaxy (MOVPE). The changes in the film structure have been investigated by applying different annealing processes which are exsitu ... -
In-situ thermal cleaning of the sapphire substrate and temperature effect on epitaxial AlN
Merve Nur Koçak; Gamze Yolcu; Sabit Horoz; İsmail Altuntaş; İlkay Demir (3.09.2022)The impact of thermal surface cleaning on epitaxial AlN thin films grown on sapphire is investigated in this study at various temperatures. The sapphire substrate is cleaned in a hydrogen environment. Structural, optical, ... -
Influence of the PALE growth temperature on quality of MOVPE grown AlN/Si (111)
Altuntas, İsmail; Koçak, Merve Nur; Yolcu, Gamze; Budak, Hasan Feyzi; Kasapoğlu, A. Emre; Horoz, Sabit; Gür, Emre; Demir, İlkay (02.02.2021)at different growth temperatures by metal organic vapor phase epitaxy (MOVPE) technique. The oxygen (O) and silicon (Si) concentrations of grown PALE-AlN epilayers and interface between epilayer and substrate were ... -
Nucleation layer temperature effect on AlN epitaxial layers grown by metalorganic vapour phase epitaxy
Şimşek, İrem; Yolcu, Gamze; Koçak, Merve Nur; Pürlü, Kağan; Altuntas, İsmail; Demir, İlkay (20.11.2021)AlN samples have been grown on sapphire substrate using nucleation layers (NLs) having different growth temperatures. The growth temperature of the NL has been varied over a wide range of temperatures highlight the effects ... -
Numerical simulation of linear and nonlinear optical properties in heterostructure based on triple Gaussian quantum wells: effects of applied external fields and structural parameters
Altuntas, İsmail; Mora-Ramos, M. E.; Dakhlaoui, H.; Ungan, Fatih (26.07.2021)In this work, we present a theoretical simulation of the impact of applied external fields and structural parameters on the total (linear plus nonlinear) optical absorption coefficient (TOAC) and total refractive relative ... -
Vcsel tabanlı yüksek güçlü yarı iletken lazerler
Altuntaş, İsmail (15.01.2021)VCSEL’ler (vertical-cavity surface-emitting laser, düşey- kovuklu yüzey-ışımalı lazer) yirmi yılı aşkın bir süredir giderek gelişen veri iletişimi (datacom) alanının anahtar bileşenlerinden birisidir. Bunun yanında son ... -
Yüksek Güç-Frekans Uygulamaları Için MOCVD ile Epitaksiyel AlN Kristalinin Büyütülmesi, Katkılanması, Karakterizasyonu ve Aygıt Üretimi
Altuntaş, İsmail (15.03.2021)Bu projede yüksek güç-frekans uygulamaları için MOCVD (metal organik kimyasal buhar depolama) ile epitaksiyel AlN kristalinin büyütülmesi, katkılanması, karakterizasyonu ve aygıt üretimi yapılarak diyot karakteristiklerinin ... -
ZnO/Al2O3 layered structures deposited by RF magnetron sputtering on glass: growth characteristics, optical properties, and microstructural analysis
Altuntaş, İsmail (12.07.2021)In this study, Al2O3 thin films of different thicknesses (50 nm, 100 nm, 150 nm, 200 nm, and 250 nm) were, first, grown using RF magnetron sputtering technique on glass substrate at 30 °C temperature, with 120Wpower value. ...