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Improvement of quantum efficiency by
employing active-layer-friendly lattice-matched
InAlN electron blocking layer in green lightemitting diodes
Hee Jin Kim, Suk Choi, Seong-Soo Kim, Jae-Hyun Ryou, P. Douglas Yoder,
Russell D. Dupuis, Alec M. Fischer, Kewei Sun, and Fernando A. Ponce
APPLIED PHYSICS LETTERS 96, 101102 (2010)
D.J. Sun
Outline
• Introduction
• Experiment
• Results and discussion
• Conclusion
• References
Introduction
• Achieved using lattice-matched InAlN
electron-blocking layers.
• Found to significantly depend on the InAlN
growth temperature.
• In the peak internal quantum efficiency.
Experiment
p-electrode
Doping Mg In0.03Al0.97N
P~1×1020cm -3
Doping Mg In0.03Al0.97N
P~2×1018cm-3
In0.18Al0.92N EBL(20nm)
MQW
Five period
In0.25Ga0.75N/GaN(2.5/11nm)
n-electrode
n-GaN(3µm)
Sapphire substrate
Experiment
5.14eV
4.21eV
LTFIG.1. Electronic band diagram of the active-region-friendly
green LED structure with an In0.18Al0.82N EBL (black) compared to one
with an Al0.30Ga0.70N EBL (red in color online and gray in print).
Results and discussion
FIG. 2. Microscopic surface morphology image of
In0.18Al0.82N layers measured by atomic force microscopy
5 × 5 µm² for (a) HT-InAlN EBL and (b) LT-InAlN EBL.
Conclusion
• InAlN EBL is an effective method to effect of the
luminous intensity enhancement and mitigation of the
efficiency decrease.
• superior for the case of LT-InAlN EBLs compared to
HT-InAlN EBLs.
• This InAlN EBL can also be applied to blue and
violet visible LEDs.
References
• Hee Jin Kim, Suk Choi, Seong-Soo Kim, Jae-Hyun Ryou,
P. Douglas Yoder,Russell D. Dupuis, Alec M. Fischer,
Kewei Sun, and Fernando A. Ponce “Improvement of
quantum efficiency by employing active-layerfriendly”APPLIED PHYSICS LETTERS 96, 101102
(2010)
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