Nanocrystalline undoped beta-Ga2O3 and Dy3+-doped beta-Ga2O3 were prepared through a Pechini-type sol-gel process. All the samples began to crystallize at 600degreesC, and the crystallinity increased with the increase of annealing temperatures until 1000degreesC. Field emission-scanning electron microscopy study revealed that the beta-Ga2O3: Dy3+ sample is composed of aggregated particles with sizes ranging from 40 to 80 nm and spherical morphology. Undoped beta-Ga2O3 sample shows a strong blue emission peaking at 438 nm. The Dy3+, Mainly occupied the octahedral Ga3+ sites in beta-Ga2O3, shows its characteristic emissions in the blue 460-505 nm (F-4(9/2)-H-6(15/2)) and yellow 570-0600 nm (F-4(9/2)-H-6(13/2)) regions due to an efficient energy transfer from the beta-Ga2O3 host lattices. The optimum concentration for the luminescence Dy3+ is determined to be 2 atom % of Ga3+ in Ga2O3 host. (C) 2004 The Electrochemical Society. All rights reserved.