Gd1.96−xYxEu0.04O3 (x = 0.0, 0.49, 0.98, 1.47, 1.96 mol%) nanophosphors: Propellant combustion synthesis, structural and luminescence studies

• Gd1.96−xYxEu0.04O3 nanophosphors have been synthesized by propellant combustion method at low temperature (400 °C).
• The crystal structures of the phosphor were determined by using Rietveld refinement.
• The product was well characterized by PXRD, SEM, TEM, UV–Vis, etc.
• Cubic and monoclinic phases show different TL glow peak values measured under identical conditions.
• The phosphor is a promising red component for white LED.

Gd1.96−xYxEu0.04O3 (x = 0.0, 0.49, 0.98, 1.47, 1.96 mol%) nanophosphors were synthesized by propellant combustion method at low temperature (400 °C). The powder X-ray diffraction patterns of as formed Gd1.96Eu0.04O3 showed monoclinic phase, however with the addition of yttria it transforms from monoclinic to pure cubic phase. The porous nature increases with increase of yttria content. The particle size was estimated from Scherrer’s and W–H plots which was found to be in the range 30–40 nm. These results were in well agreement with transmission electron microscopy studies. The optical band gap energies estimated were found to be in the range 5.32–5.49 eV. PL emission was recorded under 305 nm excitation show an intense emission peak at  611 nm along with other emission peaks at 582, 641 nm. These emission peaks were attributed to the transition of 5D0 → 7FJ (J = 0, 1, 2, 3) of Eu3+ ions. It was observed that PL intensity increases with increase of Y content up to x = 0.98 and thereafter intensity decreases. CIE color co-ordinates indicates that at x = 1.47 an intense red bright color can be achieved, which could find a promising application in flat panel displays. The cubic and monoclinic phases show different thermoluminescence glow peak values measured under identical conditions. The response of the cubic phase to the applied dose showed good linearity, negligible fading, and simple glow curve structure than monoclinic phase indicating that suitability of this phosphor in dosimetric applications.

Figure optionsDownload as PowerPoint slide