Geometrical Shaping of InGaN Light-Emitting Diodes by Laser Micromachining
– WY Fu, KN Hui, XH Wang, KKY Wong, PT Lai, and HW Choi
IEEE Photonics Technology Letters, vol. 21, 15, pp. 1078-1080 (2009)
Geometrical shaping of InGaN light-emitting diodes (LEDs) by laser micromachining is introduced. The sapphire substrate is shaped with inclined sidewalls at 50deg, serving as a prism favoring light redirection for out-coupling from the top window. Compared to conventional cuboid LEDs with a calculated light extraction efficiency eta ext of 18.3%, these shaped LEDs offers a pronounced increase in eta ext of up to 85.2%, verified by experimental results.
