Synthesis and photoluminescence properties of Sm³⁺ doped La₂O₃ nanoparticles

Samarium-doped La₂O₃ nanocrystalline powder annealed at different temperatures has been synthesized by a very cost-effective chemical precipitation method. X-ray diffraction, transmission electron microscope, energy-dispersive X-ray (EDAX) attached to scanning electron microscope and photoluminescence spectroscopy (PL) were used to analyse the prepared nanocrystals. Samples were heated at 600 °C, 700 °C and 800 °C to increase crystallinity and observe the particle size effect on the luminescence property. The PL intensity of Sm³⁺ increases with heating from 600 to 800 °C. This is attributed to the increase of Sm³⁺ occupancy in the La³⁺ lattice sites and also the extent of the reduction in the non- radiative transition with the improvement of crystallinity. Emission intensity is found to be maximum at 1 at.% Sm3⁺ doped sample for all heating temperatures. The present material might be a promising phosphor for white light LED application. (author)