Investigation of enhanced light extraction efficiency of light emitting diodes with ZnO nanorod arrays

Numerous researches have been focused on improving the light extraction efficiency of photons generated in the active layer of light emitting diodes (LEDs). Various methods have been proposed, such as LED dies [1], flip-chip LEDs [2], surface texturing of p-GaN layer or transparent conducting layer [3], and two dimensional photonic crystals [4]. However, these methods require complex and expensive processes or may result in surface damage. Here, we report the enhanced light-output performance by growing ZnO nanorod arrays at low temperature on a top layer of GaN LEDs without thermal and structural damage to the devices.