Host-Sensitized Luminescence of Dy[sup 3+] in Nanocrystalline β-Ga[sub 2]O[sub 3] Prepared by a Pechini-Type Sol-Gel Process

Nanocrystalline undoped β ­ Ga 2 O 3 and Dy 3 + -doped β ­ Ga 2 O 3 were prepared through a Pechini-type sol-gel process. All the samples began to crystallize at 600°C, and the crystallinity increased with the increase of annealing temperatures until 1000°C. Field emission-scanning electron microscopy study revealed that the β ­ Ga 2 O 3 : Dy 3 + sample is composed of aggregated particles with sizes ranging from 40 to 80 nm and spherical morphology. Undoped β ­ Ga 2 O 3 sample shows a strong blue emission peaking at 438 nm. The Dy 3 + , mainly occupied the octahedral Ga 3 + sites in β ­ Ga 2 O 3 , shows its characteristic emissions in the blue 460-505 nm ( 4 F 9 / 2 ­ 6 H 15 / 2 ) and yellow 570-0600 nm ( 4 F 9 / 2 ­ 6 H 13 / 2 ) regions due to an efficient energy transfer from the β ­ Ga 2 O 3 host lattices. The optimum concentration for the luminescence Dy 3 + is determined to be 2 atom % of Ga 3 + in Ga 2 O 3 host.