Sol-gel synthesis and photoluminescent characteristics of Eu3+-doped Gd2O3 nanophosphors

The sol-gel method using GdCl3 and EuCl3 was used to prepare Eu3+-doped Gd2O3 nanopowders with particle sizes ranging from 50 to 200 nm. This preparation was followed by a calcination process at 800-1100∘C. The effects which the Eu/Gd composition ratio and calcination temperature had on the phosphor structure and its luminescent properties were then investigated. Phosphor structure was examined by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The results confirm that the material consists of Gd2O3:Eu3+ particles exhibiting good crystallinity. Photoluminescence and cathodoluminescence measurements of the Gd2O3:Eu3+ particles show red emission at the 612 nm (D05→F27) wavelength. The optimal molar concentration for obtaining the highest PL intensity for Gd2O3:Eu3+ was 7% of Eu3+ (calcinated at 1000∘C for 2 h).