Enhanced light collection of GaN light emitting devices by redirecting the lateral emission using nanorod reflectors.

ABSTRACT

We demonstrate a method of utilizing self-assembled nanorod array reflectors to collect the laterally propagating guided modes from a light emitting diode (LED). We measure an enhancement factor of 12.2% and 18.4%, respectively, from the sidewall emission of GaN-based LEDs encompassed with 10 and 20 microm thick nanorod array reflectors. Such enhancement is found to be omnidirectional due to a broken symmetry from a randomized distribution of the nanorod array placed along the periphery of the LED's mesa. These observations indicate that the use of nanorod reflectors can efficiently redirect the propagation of the laterally guided modes to the surface normal direction.