A hole modulator for InGaN/GaN light-emitting diodes

Date
2015
Advisor
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Instructor
Source Title
Applied Physics Letters
Print ISSN
0003-6951
Electronic ISSN
1077-3118
Publisher
American Institute of Physics
Volume
106
Issue
6
Pages
063501-1 - 063501-5
Language
English
Type
Article
Journal Title
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Volume Title
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Abstract

The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active region. The essence of improving the hole injection efficiency is to increase the hole concentration in the p-GaN layer. Therefore, in this work, we have proposed a hole modulator and studied it both theoretically and experimentally. In the hole modulator, the holes in a remote p-type doped layer are depleted by the built-in electric field and stored in the p-GaN layer. By this means, the overall hole concentration in the p-GaN layer can be enhanced. Furthermore, the hole modulator is adopted in the InGaN/GaN LEDs, which reduces the effective valance band barrier height for the p-type electron blocking layer from ∼332meV to ∼294 meV at 80 A/cm2 and demonstrates an improved optical performance, thanks to the increased hole concentration in the p-GaN layer and thus the improved hole injection into the MQWs.

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Keywords
Charge injection, Electric fields, Electron injection, Gallium nitride, Heterojunction bipolar transistors, Hole concentration, Light modulators, Modulators, Semiconducting indium compounds, Semiconductor quantum wells, Active regions, Built - in electric fields, Electron blocking layer, Improved hole injection, Ingan/gan leds, Ingan/gan lightemitting diodes (LEDs), Optical performance, Valance band barriers, Light emitting diodes
Citation
Published Version (Please cite this version)