Improvement of photon extraction efficiency of GaN-based LED using micro and nano complex polymer structures

• Main Authors: Kim Hyeong-Seok, Cho Joong-Yeon, Byeon Kyeong-Jae, Park Hyoungwon, Kim Jinseung, Lee Heon
• Format: Article
• Language: English
• Published: SpringerOpen 2011-01-01
• Series: Nanoscale Research Letters
• Online Access: http://www.nanoscalereslett.com/content/6/1/578

<p>Abstract</p> <p>A micro- and nanoscale complex structure made of a high refractive index polymer (<it>n </it>= 2.08) was formed on the ITO electrode layer of an edge-emitting type GaN blue light-emitting diode (LED), in order to improve the photon extraction efficiency by suppressing total internal reflection of photons. The nanoimprint lithography process was used to form the micro- and nanoscale complex structures, using a polymer resin with dispersed TiO₂nano-particles as an imprint resin. Plasma processing, such as reactive ion etching, was used to form the micro- and nano-scale complex structure; thus, plasma-induced damage to the LED device can be avoided. Due to the high refractive index polymeric micro- and nanostructure on the ITO layer, the electroluminescence emission was increased up to 20%, compared to an identical LED that was grown on a patterned sapphire substrate to improve photon extraction efficiency.</p>