Browsing by Author "Baek, J. H."
Now showing items 1-7 of 7
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Dislocation density dependent electroabsorption in epitaxial lateral overgrown InGaN/GaN quantum structures
Sari, E.; Jang, L. W.; Baek, J. H.; Lee, I. H.; Sun, X. W.; Demir, Hilmi Volkan (Optical Society of America, 2013-01-14)We study electroabsorption (EA) behavior of InGaN/GaN quantum structures grown using epitaxial lateral overgrowth (ELOG) in correlation with their dislocation density levels and in comparison to steady state and time-resolved ... -
Electric field dependent radiative decay kinetics of polar InGaN/GaN quantum heterostructures at low fields
Sari, E.; Nizamoglu, S.; Lee, I. H.; Baek, J. H.; Demir, Hilmi Volkan (American Institute of Physics, 2009-05-29)Electric field dependent photoluminescence decay kinetics and its radiative component are studied in polar InGaN/GaN quantum heterostructures at low fields. Under externally applied electric field lower than polarization ... -
Experimental and computational analyses of electroabsorption in polar InGaN/GaN quantum zigzag heterostructures
Sarı, Emre; Özel, Tuncay; Koç, Aslı; Ju, J.-W.; Ahn, H.-K.; Lee, I.-H.; Baek, J. H.; Demir, Hilmi Volkan (IEEE, 2008-11)Traditional quantum confined Stark effect is well known to lead to strong electroabsorption in multiple quantum well (MQW) structures, yielding only red-shift of the absorption edge with the externally applied electric ... -
FRET-LEDs involving colloidal quantum dot nanophosphors
Nizamoğlu, S.; Sari, E.; Baek, J. H.; Lee, I. H.; Sun, X. W.; Demir, Hilmi Volkan (Webcom Communications, 2010)Semiconductor nanocrystal quantum dots (NQD) with their narrow and tuneable emission are promising candidates to serve as color convertors integrated on light-emitting diodes (LEDs). The use of nonradiative energy transfer, ... -
Green/yellow solid state lighting via radiative and nonradiative energy transfer involving colloidal semiconductor nanocrystals
Nizamoglu, S.; Sari, E.; Baek, J. H.; Lee, I. H; Demir, Hilmi Volkan (IEEE, 2009-08-05)LEDs made of In(x)Ga(1-x)N and (Al(x)Ga(1-x))(1-y)In(y)P suffer from significantly reduced quantum efficiency and luminous efficiency in the green/yellow spectral ranges. To address these problems, we present the design, ... -
Nonradiative resonance energy transfer directed from colloidal CdSe/ZnS quantum dots to epitaxial InGaN/GaN quantum wells for solar cells
Nizamoglu, S.; Sari, E.; Baek, J. H.; Lee, I. H.; Demir, Hilmi Volkan (Wiley, 2010-06-04)We report on Förster-type nonradiative resonance energy transfer (NRET) directed from colloidal quantum dots (QDs) to epitaxial quantum wells (QWs) with an efficiency of 69.6% at a rate of 1.527 ns-1 for potential application ... -
Opposite carrier dynamics and optical absorption characteristics under external electric field in nonpolar vs. polar InGaN/GaN based quantum heterostructures
Sari, E.; Nizamoglu, S.; Choi, J H.; Lee, S J.; Baik, K H.; Lee, I. H.; Baek, J. H.; Hwang, S M.; Demir, Hilmi Volkan (Optical Society of America, 2011)We report on the electric field dependent carrier dynamics and optical absorption in nonpolar a-plane GaN-based quantum heterostructures grown on r-plane sapphire, which are surprisingly observed to be opposite to those ...