Preparation and characterization of the Eu3+ doped perovskite nanosheet phosphor:: La0.90Eu0.05Nb2O7

Eu3+-doped perovskite nanosheets, La0.90Eu0.05Nb2O7, have been prepared by the soft chemical exfoliation reaction of K1-xHxLa0.90Eu0.05Nb2O7 with a tetrabuthylammonium hydroxide aqueous solution. The resulting colloidal La0.90Eu0.05Nb2O7 nanosheet suspension exhibits photoluminescence emission from the D-5(0) to F-7(J) manifold transitions of Eu3+ by either direct excitation of Eu3+ or host excitation, whereas no host emission was observed at room temperature. In the case of the bulk precursors K1-xHxLa0.90Eu0.05Nb2O7, the direct excitation yields more intense emission than the host excitation. Oil the contrary, the most intense emission from the La0.90Eu0.05Nb2O7 nanosheets was observed by exciting at the broad excitation band maximum (353 nm). The difference in the photoluminescence properties between the La0.90Eu0.05Nb2O7 nanosheets and their bulk precursors seems to be related to the dimensionality of these host structures and the confinement of the energy-transfer process between the host layer units and Eu3+ activators.