Fabrication of highly a-axis-oriented Gd2O3:Eu3+ thick film and its luminescence properties

Dense and transparent Gd2O3:Eu3+ thick films were prepared from the inorganic salt and 2-methoxyethanol solution containing polyvinylpyrrolidone (PVP) via sol-gel technique. It was found that the films exhibited a preferred a-axis orientation, the preferential orientation parameter was 83.8%, and they possessed of a high intensity ratio of 5D0 → 7F2/5D0 → 7F1. The correlation between structure and luminescent properties of the film was tentatively discussed. These results indicated that PVP played an important role in the formation of Gd2O3:Eu3+ thick films, suppressing the stress, changing the growth direction of the films from 〈1 1 1〉 to 〈1 0 0〉 orientation and improving the covalency of Eu-O bonds and the energy transfer from S6 sites to C2 sites. The Gd2O3:Eu3+ thick film prepared with PVP showed a superior luminescent property, which implies that it will have promising applications in high-spatial-resolution X-ray imaging and flat panel display devices.