Device characterization(1-2)
Fig. 3. (a) Near-field emission pattern profiles for the SDI-LED structure (thick solid
line) and the reference (thin solid line). The insets are the near-field images of the
corresponding devices. The donut-shaped emission patterns (instead of uniform or
Gaussian profiles) for the broad mesa surface emission are due to higher-order mode
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operation of the laser excitation source.
Device characterization(1-3)
Fig. 3.(b) Near-field image of the SDI-LED structure when pump beam
is tightly focused at the center of the circular mesa.
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Device characterization(1-4)
Fig. 4.
(b) Computer-simulated far-field patterns of
the corresponding devices.
(a) Far-field patterns of the SDI-LED
structures (with sidewall anglesof = 20 ; 30 ,
and 40 ) and reference.
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Conclusion
• The LED structure, which was characterized by
angled mesa sidewalls, efficiently deflected the
photons that would otherwise have been guided
laterally along the GaN epilayer.
• LED structure enhanced the overall surface
emission intensity via the proposed mechanism
by up to 3.1 times for a sidewall angle of 30 .
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References
• Jae-Soong Lee, Joonhee Lee, Sunghwan Kim,
and Heonsu Jeon”GaN-Based Light-Emitting
Diode Structure With Monolithically Integrated
Sidewall Deflectors for Enhanced Surface
Emission ” 2006 IEEE
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Thanks for your attention !
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