Luminescence properties of Ln doped BaMoO (Ln = Sm and Dy) phosphors under UV excitation.

Ln doped BaMoO (Ln = Sm and Dy) nanoparticles have been synthesized successfully using ethylene glycol as a solvent. All the prepared samples are well indexed into the pure scheelite-type tetragonal structure of BaMoO, the doping of trivalent ions (Ln) in to the bivalent host ions (Ba) sites of the BaMoO do not change the pure tetragonal structure of BaMoO although there is a charge difference between Ba and Ln. The SEM image of the prepared BaMoO samples shows a number of uniform shuttle-like nanocrystalline with protrusion in the middle. The doping of Ln ions do not change the morphology of the BaMoO. The photoluminescence study has been carried in detail by measuring the excitation and emission spectra of the prepared samples. The excitation spectrum consists of a broad band with a maximum at about 268 nm thereby demonstrating the transfer of energy from MoO groups to the doped Ln ions. Yellow emission is dominated over blue in case of Dy doped BaMoO and in Sm doped BaMoO red emission dominated over other lights under UV excitation. The luminescence intensity is highest at 10 at.% Ln under the UV excitation. Under this UV excitation BaMoO:Sm exhibits strong orange-red and BaMoO:Dy greenish-yellow emissions. Excitation of Dy in thin film of BaMoO emits an intense yellow color which could be applicable in the field of biological assays and biological fluorescence labeling.