Abstract
Current injection efficiency and its impact on efficiency-droop in InGaN single quantum well (QW) based light-emitting diodes (LEDs) are investigated. The analysis is based on current continuity relation for drift and diffusion carrier transport across the QW-barrier system. A self-consistent 6-band k · p method is used to calculate the band structure for InGaN QW. The analysis indicates that the internal quantum efficiency in the conventional 24- In0.28Ga0.72N-GaN QW structure reaches its peak at low injection current density and reduces gradually with further increase in current due to the large carrier thermionic emission. Structures combining 24- In 0.28Ga0.72N QW with 15- Al0.1Ga0.9N barriers show slight reduction in quenching of the injection efficiency as current density increases. The use of 15- Al0.83In0.17N barriers shows significant reduction in efficiency-droop (10% reduction of the internal quantum efficiency at current density of 620 A/cm2). Thus, InGaN QWs employing thin layers of larger bandgap AlInN barriers suppress the efficiency-droop phenomenon significantly.
Original language | English (US) |
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Pages (from-to) | 1119-1124 |
Number of pages | 6 |
Journal | Solid-State Electronics |
Volume | 54 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2010 |
Externally published | Yes |
Keywords
- Efficiency-droop
- III-Nitride
- InGaN QWs
- Light-emitting diodes
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering