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

GaN‐based light‐emitting diode (LED) with SiO2 photonic 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. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)