Improvement of GaN-based LED with SiO2 photonic crystal on an ITO film by holographic lithography

Abstract

GaN-based light-emitting diode (LED) with SiO2 photonie crystals (PCs) structure made by holographic lithography on an indium-tin-oxide (ITO) film was fabricated. The PCs made on SiO2 but an ITO film both improves the light extraction efficiency of the GaN-based LED and prevents the sheet resistance increasing of the ITO film from the dry etching damage. It was found that the forward voltage at 20 mA of the GaN-based LED with SiO2 PCs on an ITO film was 1.9% higher than the GaN-based LED with a planar ITO film only. The output power of GaN-based LED with SiO2 PCs on an ITO film at 20mA was 17.1%, 26.5% and 125.3% higher than that of the GaN-based LEDs with the planar SiO2/ITO, planar ITO or Ni/Au surface layers, respectively.