Light extraction analysis of GaN-based light-emitting diodes with surface texture and/or patterned substrate

Light extraction analysis of GaN-based light-emitting diodes (LEDs) with Monte Carlo ray tracing is presented. To obtain high light extraction efficiency, periodic structures introduced on the top surface and/or on the substrate of various types of LED are simulated, including wire bonding, flip chip and Thin GaN. Micro pyramid array with an apex angle from 20° to 70° is shown to effectively improve the light extraction efficiency. In addition, for an LED encapsulated within an epoxy lens, the patterned substrate with pyramid array is found to be a more effective way to increase light extraction efficiency than the surface texture.