GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer

Abstract

Enhancement of light extraction in a GaInN light-emitting diode (LED) employing a conductive omnidirectional reflector (ODR) consisting of GaN, an indium-tin oxide (ITO) nanorod low-refractive-index layer, and an Ag layer is presented. An array of ITO nanorods is deposited on p-type GaN by oblique-angle electron-beam deposition. The refractive index of the nanorod ITO layer is 1.34 at 461 nm, significantly lower than that of dense ITO layer, which is n=2.06. The GaInN LEDs with GaN/low-n ITO/Ag ODR show a lower forward voltage and a 31.6% higher light-extraction efficiency than LEDs with Ag reflector. This is attributed to enhanced reflectivity of the ODR that employs the low-n ITO layer. (c) 2006 American Institute of Physics.