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Applied Optics

Applied Optics


  • Editor: Joseph N. Mait
  • Vol. 52, Iss. 7 — Mar. 1, 2013
  • pp: 1358–1367

Light extraction efficiency analysis of GaN-based light-emitting diodes with nanopatterned sapphire substrates

Jui-Wen Pan, Pei-Jung Tsai, Kao-Der Chang, and Yung-Yuan Chang  »View Author Affiliations

Applied Optics, Vol. 52, Issue 7, pp. 1358-1367 (2013)

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In this paper, we propose a method to analyze the light extraction efficiency (LEE) enhancement of a nanopatterned sapphire substrates (NPSS) light-emitting diode (LED) by comparing wave optics software with ray optics software. Finite-difference time-domain (FDTD) simulations represent the wave optics software and Light Tools (LTs) simulations represent the ray optics software. First, we find the trends of and an optimal solution for the LEE enhancement when the 2D-FDTD simulations are used to save on simulation time and computational memory. The rigorous coupled-wave analysis method is utilized to explain the trend we get from the 2D-FDTD algorithm. The optimal solution is then applied in 3D-FDTD and LTs simulations. The results are similar and the difference in LEE enhancement between the two simulations does not exceed 8.5% in the small LED chip area. More than 104 times computational memory is saved during the LTs simulation in comparison to the 3D-FDTD simulation. Moreover, LEE enhancement from the side of the LED can be obtained in the LTs simulation. An actual-size NPSS LED is simulated using the LTs. The results show a more than 307% improvement in the total LEE enhancement of the NPSS LED with the optimal solution compared to the conventional LED.

© 2013 Optical Society of America

OCIS Codes
(230.3670) Optical devices : Light-emitting diodes
(080.1753) Geometric optics : Computation methods
(220.4241) Optical design and fabrication : Nanostructure fabrication
(050.6624) Diffraction and gratings : Subwavelength structures

ToC Category:
Optical Devices

Original Manuscript: September 20, 2012
Revised Manuscript: January 2, 2013
Manuscript Accepted: January 17, 2013
Published: February 22, 2013

Jui-Wen Pan, Pei-Jung Tsai, Kao-Der Chang, and Yung-Yuan Chang, "Light extraction efficiency analysis of GaN-based light-emitting diodes with nanopatterned sapphire substrates," Appl. Opt. 52, 1358-1367 (2013)

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