Integrated light-emitting diodes (LEDs) that operate in the UV spectral region were fabricated using GaN layers grown on sapphire substrates by metal-organic vapor phase epitaxy. Schottky-type LEDs and metal-oxide-semiconductor (MOS) LEDs were realized. The near-band-edge emission of GaN was observed in the electroluminescent spectra with reversed bias under pulsed-voltage conditions. The insertion of an aluminum oxide layer in the GaN-based LED leads to an increase in electroluminescent intensity. (C) 2007 American Vacuum Society.