DocumentCode :
1758118
Title :
Green-Emitting (\\lambda =525~{\\rm nm}) InGaN/GaN Quantum Dot Light Emitting Diodes Grown on Quantum Dot Dislocation Filters
Author :
Banerjee, Adrish ; Frost, Thomas ; Jahangir, Shafat ; Bhattacharya, Pallab
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of Michigan, Ann Arbor, MI, USA
Volume :
50
Issue :
4
fYear :
2014
fDate :
41730
Firstpage :
228
Lastpage :
235
Abstract :
We have investigated the dislocation filtering characteristics of InGaN/GaN quantum dot multilayers grown at the substrate/active layer interface along the c-axis. Etch pit dislocation density measurements reveal a reduction in defect density by a factor of 5, from ~ 5×108 cm-2 to ~ 9.8×107 cm-2 in a GaN overlayer with an optimized quantum dot multilayer. This is accompanied by a reduction of electron and hole trap densities in the GaN layer by a factor of 3 and an increase in the luminescence efficiency of green-emitting In0.35Ga0.65N/GaN quantum dots grown atop such filters. Green-emitting (λ = 525 nm) quantum dot light emitting diodes having optimized dislocation filter show marked improvement in their current-voltage and light-current characteristics and in their external quantum efficiency. The peak efficiency is achieved at an injection level of 27 A/cm2.
Keywords :
III-V semiconductors; dislocation density; electron traps; gallium compounds; hole traps; indium compounds; light emitting diodes; luminescence; optical filters; semiconductor quantum dots; InGaN-GaN; current-voltage characteristics; defect density; electron trap density; etch pit dislocation density; external quantum efficiency; green emitting quantum dot light emitting diodes; hole trap density; light-current characteristics; luminescence efficiency; quantum dot dislocation filters; quantum dot multilayers; substrate-active layer interface; wavelength 525 nm; Density measurement; Electron traps; Gallium nitride; III-V semiconductor materials; Light emitting diodes; Quantum dots; Temperature measurement; Dislocation filter; gallium nitride; light emitting diode; molecular beam epitaxy; quantum dots;
fLanguage :
English
Journal_Title :
Quantum Electronics, IEEE Journal of
Publisher :
ieee
ISSN :
0018-9197
Type :
jour
DOI :
10.1109/JQE.2014.2304954
Filename :
6733329
Link To Document :
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