Improving hole injection efficiency by manipulating the hole transport mechanism through p-type electron blocking layer engineering
Author(s)
Date
2014Source Title
Optics Letters
Print ISSN
0146-9592
Publisher
Optical Society of America
Volume
39
Issue
8
Pages
2483 - 2486
Language
English
Type
ArticleItem Usage Stats
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Abstract
The p-type AlGaN electron blocking layer (EBL) is widely used in InGaN/GaN light-emitting diodes (LEDs) for electron overflow suppression. However, a typical EBL also reduces the hole injection efficiency, because holes have to climb over the energy barrier generated at the p-AlGaN/p-GaN interface before entering the quantum wells. In this work, to address this problem, we report the enhancement of hole injection efficiency by manipulating the hole transport mechanism through insertion of a thin GaN layer of 1 nm into the p-AlGaN EBL and propose an AlGaN/GaN/AlGaN-type EBL outperforming conventional AlGaN EBLs. Here, the position of the inserted thin GaN layer relative to the p-GaN region is found to be the key to enhancing the hole injection efficiency. InGaN/ GaN LEDs with the proposed p-type AlGaN/GaN/AlGaN EBL have demonstrated substantially higher optical output power and external quantum efficiency.
Keywords
EfficiencyGallium nitride
Hole mobility
Light emitting diodes
Electron blocking layer
Electron overflow
External quantum efficiency
GaN layers
Hole injection
Hole transport mechanism
Ingan/gan lightemitting diodes (LEDs)
Optical output power
Electron injection