Browsing by Author "Altuntas, I."
Now showing items 1-8 of 8
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Distributed contact flip chip InGaN/GaN blue LED; comparison with conventional LEDs
Genc, M.; Sheremet, V.; Elci, M.; Kasapoglu, A. E.; Altuntas, I.; Demir, I.; Egin, G.; Islamoglu, S.; Gur, Emre; Muzafferoglu, N.; Elagoz, S.; Gulseren, O.; Aydinli, A. (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2019)This paper presents high performance, GaN/InGaN-based light emitting diodes (LEDs) in three different device configurations, namely Top Emitting (TE) LED, conventional Flip Chip (FC) and Distributed Contact (DC) FC. Series ... -
Growth kinetics of O-polar BexMgyZn1-x-yO alloy: Role of Zn to Be and Mg flux ratio as a guide to growth at high temperature
Ullah, M. B.; Avrutin, V.; Nakagawara, T.; Hafiz, S.; Altuntas, I.; Ozgur, U.; Morkoc, H. (AMER INST PHYSICS, 2017)We studied the effect of the substrate temperature, in the range from 450 degrees C to 500 degrees C, on the required Zn to (Be + Mg) flux ratio for plasma-assisted molecular beam epitaxy growth of O-polar BexMgyZn1-x-yO ... -
The hydrostatic pressure and temperature effects on hydrogenic impurity binding energies in GaAs/InxGa1-xAs/GaAs square quantum well
Baser, P.; Altuntas, I.; Elagoz, S. (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2016)We have calculated the ground state binding energy using variational methods and the effective mass approximation for the hydrogenic impurity in square quantum well structure made up of GaAs/InGaAs/GaAs epilayers under the ... -
InGaN stress compensation layers in InGaN/GaN blue LEDs with step graded electron injectors
Sheremet, V.; Gheshlaghi, N.; Sozen, M.; Elci, M.; Sheremet, N.; Aydinli, A.; Altuntas, I.; Ding, K.; Avrutin, V.; Ozgur, U.; Morkoc, H. (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2018)We investigate the effect of InGaN stress compensation layer on the properties of light emitting diodes based on InGaN/GaN multiple quantum well (MQW) structures with step graded electron injectors. Insertion of an InGaN ... -
Microstructural Evolution of MOVPE Grown GaN by the Carrier Gas
Demir, I.; Altuntas, I.; Kasapoglu, A. E.; Mobtakeri, S.; Guer, E.; Elagoz, S. (PLEIADES PUBLISHING INC, 2018)We report the effect of total carrier gas flow of GaN during both GaN nucleation layer and high temperature GaN growth steps on structural, optical, electrical and morphological properties. The formation of dislocations ... -
The role of ITO resistivity on current spreading and leakage in InGaN/GaN light emitting diodes
Sheremet, V.; Genc, M.; Elci, M.; Sheremet, N.; Aydinli, A.; Altuntas, I.; Ding, K.; Avrutin, V.; Ozgur, U.; Morkoc, H. (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2017)The effect of a transparent ITO current spreading layer on electrical and light output properties of blue InGaN/GaN light emitting diodes (LEDs) is discussed. When finite conductivity of ITO is taken into account, unlike ... -
Simulation of Highly Reflective GaN/AlxGa1-xN Distributed Bragg Reflector Structure for UV-Blue LEDs
Alaydin, B. O.; Altuntas, I.; Tuzemen, E. Senadim; Elagoz, S. (AMER SCIENTIFIC PUBLISHERS, 2018)In this study, we showed theoretically enhanced reflectance characteristics of nitride based blue Light Emitting Diode (LED) by adding GaN/AlxGa1-xN Distributed Bragg Reflector (DBR) between n-contact layer and GaN buffer ... -
Two-step passivation for enhanced InGaN/GaN light emitting diodes with step graded electron injectors
Sheremet, V.; Genc, M.; Gheshlaghi, N.; Elci, M.; Sheremet, N.; Aydinli, A.; Altuntas, I.; Ding, K.; Avrutin, V.; Ozgur, U.; Morkoc, H. (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2018)Enhancement of InGaN/GaN based light emitting diode performance with step graded electron injectors through a two-step passivation is reported. Perimeter passivation of LED dies with SiO2 immediately following ICP mesa ...