J.Y. Yang
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Outline
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Introduction
Device Structure
Simulation Results
Conclusion
References
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Introduction
• The efficiency droop is a serious restriction for highpower applications.
• The physical origin of droop including carrier
delocalization, Auger recombination, poor hole
injection, and electron leakage have been reported.
• Among them, the insufficient hole injection and
electron leakage may play an important role.
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Introduction
• Therefore, in this letter, the quantum barriers are
modified by alternating AlGaN barriers with GaN
barriers along the growth direction in MQWs for
better LED performance, which is referred as the
alternating quantum barriers.
• Moreover, the increase of Al concentration in the
alternating barriers can further enhance the
performance of our designed structure.
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Device Structure
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Simulation Results
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Simulation Results
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Simulation Results
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Conclusion
• In conclusion, InGaN LEDs with special
modifications for the quantum barriers by alternating
AlGaN barriers with GaN barriers are proposed.
• Simulation shows that the electron confinement and
hole injection/transportation are efficiently improved,
and the electron leakage is reduced accordingly in the
proposed structure, due to the appropriate band
engineering.
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Conclusion
• The IQE and efficiency droop are therefore largely
improved, as compared to the counterparts with GaN
barriers or AlGaN barriers.
• Moreover, the increase of Al composition on the basis
of our designed structure can further promote the
LED performance because of the more uniform
carrier distribution.
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References
• Yujue Yang and Yiping Zeng, “Efficiency Droop Reduction in
InGaN LEDs by Alternating AlGaN Barriers With GaN
Barriers,” IEEE Photonics Technology Letters, vol. 27, NO. 8,
April 15, 2015.
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Thank you for your attention
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