Synthesis, crystal structure and temperature dependent luminescence of Eu3+ doped SrGd2O4 host: An approach towards tunable red emissions for display applications

In the present paper, an investigation on the structural and photoluminescence (PL) properties of SrGd2O4:Eu3+ ceramic phosphors synthesized by homogeneous precipitation method followed by combustion process has been reported. The samples, annealed at 1200 °C, were crystallized into orthorhombic phase without any impurities. Microscopic studies revealed the irregular morphology of the obtained ceramic phosphor particles having sizes in the range of 0.3-3 µm. The characteristic photoluminescence properties and decay curves were studied in detail as a function of Eu3+ concentration and temperature. The Eu3+ doped ceramic samples illuminated with UV light revealed the characteristic red luminescence corresponding to 5D0→7FJ transitions of Eu3+. The concentration quenching phenomenon of Eu3+ ions in the present host, analyzed in the light of ion-ion interaction, indicated multipolar interaction between Eu3+ ions. Finally, the intensity parameters (Ω2, Ω4) and various radiative properties such as stimulated emission cross-section (σe), gain band-width (σe×Δλeff) and optical gain (σe×τexp) of Eu3+ in the SrGd2O4 ceramic phosphors have been calculated by using Judd-Ofelt theory. The present phosphor system exhibited efficient red emission with high red color purity (95%) and adequate thermal stability even at 200 °C. Present research broadly indicated the suitability of SrGd2O4:Eu3+ ceramic phosphor for display applications.