Improving the optical performance of InGaN light-emitting diodes by altering light reflection and refraction with triangular air prism arrays

Ji Hye Kang; Hyung Gu Kim; S Chandramohan; Hyun Kyu Kim; Hee Yun Kim; Jae Hyoung Ryu; Young Jae Park; Yun Seon Beak; Jeong-Sik Lee; Joong Seo Park; Volodymyr V Lysak; Chang-Hee Hong

doi:10.1364/OL.37.000088

Improving the optical performance of InGaN light-emitting diodes by altering light reflection and refraction with triangular air prism arrays

Opt Lett. 2012 Jan 1;37(1):88-90. doi: 10.1364/OL.37.000088.

Authors

Ji Hye Kang¹, Hyung Gu Kim, S Chandramohan, Hyun Kyu Kim, Hee Yun Kim, Jae Hyoung Ryu, Young Jae Park, Yun Seon Beak, Jeong-Sik Lee, Joong Seo Park, Volodymyr V Lysak, Chang-Hee Hong

Affiliation

¹ Semiconductor Physics Research Center, School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju 561-756, South Korea.

PMID: 22212800
DOI: 10.1364/OL.37.000088

Abstract

The effect of triangular air prism (TAP) arrays with different distance-to-width (d/w) ratios on the enhancement of light extraction efficiency (LEE) of InGaN light-emitting diodes (LEDs) is investigated. The TAP arrays embedded at the sapphire/GaN interface act as light reflectors and refractors, and thereby improve the light output power due to the redirection of light into escape cones on both the front and back sides of the LED. Enhancement in radiometric power as high as 117% and far-field angle as low as 129° are realized with a compact arrangement of TAP arrays compared with that of a conventional LED made without TAP arrays under an injection current of 20 mA.