By Topic

Improving Light Extraction Efficiency of GaN-Based LEDs by Al _{bm x} Ga _{{\bf 1}{bm -}{bm x}} N Confining Layer and Embedded Photonic Crystals

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

5 Author(s)
Hui Gao ; Sch. of Inf. Sci. & Eng., Shandong Univ., Jinan, China ; Kang Li ; Fan-Min Kong ; Xin-Lian Chen
more authors

The interaction of low-order modes with photonic crystals (PhCs) has been a promising technique to increase light extraction efficiency (LEE) of LEDs. In this paper, numerical simulations based on the finite-difference time-domain method were carried out to explore different mechanisms that can effectively improve this interaction. The results showed that deeply etched PhCs have inefficient light extraction since they would decrease the effective thickness of the unetched layer and cut off some guided modes. By applying the AlxGa1-xN confining layer, the distribution of guided modes was changed. The cap layer mode was isolated from the GaN buffer, and larger LEE was achieved. Furthermore, dramatic increments with oscillations were found in the LEE by using embedded PhCs. Resonances of the Bloch mode localized within these PhCs, which caused the oscillations, were further modified by a shallow AlxGa1-xN confining layer. With the optimized parameters, over eightfold increment in LEE was achieved. In addition, dislocations caused by higher Al content and thicker AlxGa1-xN layer were avoided. This proposed structure could be a very promising candidate for high extraction efficiency LEDs.

Published in:

Selected Topics in Quantum Electronics, IEEE Journal of  (Volume:18 ,  Issue: 6 )