Investigation of p-type depletion doping for InGaN/GaN-based light-emitting diodes
Author(s)
Date
2017Source Title
Applied Physics Letters
Print ISSN
0003-6951
Publisher
American Institute of Physics Inc.
Volume
110
Issue
3
Pages
033506-1 - 033506-5
Language
English
Type
ArticleItem Usage Stats
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Abstract
Due to the limitation of the hole injection, p-type doping is essential to improve the performance of InGaN/GaN multiple quantum well light-emitting diodes (LEDs). In this work, we propose and show a depletion-region Mg-doping method. Here we systematically analyze the effectiveness of different Mg-doping profiles ranging from the electron blocking layer to the active region. Numerical computations show that the Mg-doping decreases the valence band barrier for holes and thus enhances the hole transportation. The proposed depletion-region Mg-doping approach also increases the barrier height for electrons, which leads to a reduced electron overflow, while increasing the hole concentration in the p-GaN layer. Experimentally measured external quantum efficiency indicates that Mg-doping position is vitally important. The doping in or adjacent to the quantum well degrades the LED performance due to Mg diffusion, increasing the corresponding nonradiative recombination, which is well supported by the measured carrier lifetimes. The experimental results are well numerically reproduced by modifying the nonradiative recombination lifetimes, which further validate the effectiveness of our approach.
Keywords
Charge injectionHole concentration
Semiconducting indium compounds
Semiconductor quantum wells
Depletion region
Electron blocking layer
Electron overflow
External quantum efficiency
InGaN/GaN multiple quantum well light emitting diodes
Non-radiative recombinations
Numerical computations
Valence band barriers
Light emitting diodes