High light extraction efficiency light-emitting diodes grown on bulk GaN and sapphire substrates using vertical transparent package

High light extraction efficiency (LEE) of 75.86% and 77% for light-emitting diodes (LEDs) grown on free-standing GaN and patterned sapphire substrates, respectively, are demonstrated using novel vertical transparent LED (VT-LED) package. Compared to conventional silver header package with consistent external quantum efficiency (EQE) and LEE, enhancement of similar to 14% and similar to 12% for GaN and sapphire chips, respectively, are also demonstrated up to 100 A/cm(2) under DC operations without any current crowding issues. Also, using high refractive index materials (n similar to 2.1) between LED and ZnO stand, LEE of 81% and 82% for blue and green GaN chips can be achieved.