Enhanced output of flip-chip light-emitting diodes with a sidewall reflector

This investigation describes the development of InGaN–GaN light-emitting diode with a sidewall reflector for increasing the light output. On LED sidewall, the Ag film and the SiO2 film form an omni-directional sidewall reflector. The sidewall reflector effectively reflects isotropic photons, and significantly enhances the probability that the photons emitted in the near horizontal and in-plane directions escape outside of the LED from the substrate surface avoiding the light absorption by the n-contact, n-pat and the solders. At 20 mA, the light output of the flip-chip LEDs with sidewall reflectors is 10.9% higher than the conventional flip-chip LEDs (CFC LEDs).