High-quality GaN films were grown on epitaxial AlN/sapphire templates by metal-organic vapor phase epitaxy. The Hall mobility as high as 790 cm(2)/Vs with the carrier concentration of 7.6 x 10(16) cm(-3) at 300 K along with low dislocation density of 5 x 10(7) cm(-2) have been achieved. The X-ray rocking curve full-width at half-maximum were 61 and 232 arcsec for the (0004) and (20 (2) over bar4) reflections, respectively. Atomic force microscopy images showed smooth surface morphology and clear step formation. Additionally, pit terminations could be hardly found. Photoluminescence measurement revealed a higher intensity near the band edge. (C) 2002 Elsevier Science B.V. All rights reserved.