Optical Enhancement of 450-nm GaN Light Emitting Diodes with Metallic Reflective Layer

摘要

The optical enhancement of 450-nm emitted GaN light emitting diodes (LEDs) is facilely obtained by using a reflective substrate. The reflection layer was synthesized by evaporation of Ag, Au or Ni (100-nm thickness) on the sapphire substrate of the epitaxial GaN LED. Remarkable efficiency improvement was observed for the Ag reflective substrate with similar to 95% reflectivity at the wavelength of 450 nm. The GaN LED with the Ag reflection exhibited an enhancement of 160% compared with the conventional GaN LED.