Geometrical Shaping of InGaN Light-Emitting Diodes by Laser Micromachining

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
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of 18.3%, these shaped LEDs offers a pronounced increase in eta
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of up to 85.2%, verified by experimental results.