Green-Emitting $(\lambda=525~{\rm nm})$ InGaN/GaN Quantum Dot Light Emitting Diodes Grown on Quantum Dot Dislocation Filters
| Autor: | Shafat Jahangir, Pallab Bhattacharya, Animesh Banerjee, Thomas Frost |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
business.industry Gallium nitride Condensed Matter Physics Atomic and Molecular Physics and Optics Active layer law.invention Overlayer Condensed Matter::Materials Science chemistry.chemical_compound chemistry law Quantum dot Optoelectronics Quantum efficiency Electrical and Electronic Engineering Dislocation business Light-emitting diode Molecular beam epitaxy |
| Zdroj: | IEEE Journal of Quantum Electronics. 50:228-235 |
| ISSN: | 1558-1713 0018-9197 |
| DOI: | 10.1109/jqe.2014.2304954 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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