Luminescent Gd1.9Eu0.1O3 nanospheres for flat panel displays

Gd_1.9Eu_0.1O₃ spherical shaped nanophosphors were successfully prepared by a large-scale and facile solution based citrate-metal complex method without using any catalyst or template followed by subsequent heat treatment process. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) measurements were done to evaluate the phase composition, surface morphology and luminescent properties of the nanophosphors. Complete formation of Gd_1.9Eu_0.1O₃ takesplace at a relatively low temperature of about 700 °C and found that the crystallinity of the samples increases with increase of sintering temperature. Observation of increase of photoluminescent emission intensity of the samples can be correlated with the improved crystallinity, uniform morphology, particle size, reduced defects, and proper diffusion of Eu³⁺ in to the crystal structure of Gd₂O₃. Higher asymmetric ratio results in profound red emission (612 nm) due to ⁵D₀-⁷F₂ transition and found that photoluminescence intensity get saturated for samples prepared above 800 °C. CIE chromaticity coordinates obtained are found to be very close to standard red emission. The existence of strong red emission from spherical shaped Gd_1.9Eu_0.1O₃ nanophosphor corresponding to ⁵D₀-⁷F₂ transition (612 nm) of Eu³⁺ under UV light excitation make it a potential candidate for applications in fluorescent lamps and flat panel displays.