Luminescence studies of needle like structured Sr2Ca(1-x)TeO6:xEu3+ phosphors for solid state lighting applications

Abstract

The structural and photoluminescence studies of a series of Sr₂Ca_(1-x)TeO₆:xEu³⁺ phosphors synthesized through solid state reaction method were investigated in this work. The phosphor exhibits needle like morphology which is advantageous for its use in photovoltaic cells and lighting applications. On exciting Sr₂CaTeO₆:Eu³⁺ phosphors with blue light (λ = 464 nm), the phosphors exhibit bright red emission at 615 nm, which corresponds to the transition of Eu³⁺ in Sr₂CaTeO₆ host, originating from ⁵D₀→⁷F₂ electric dipole transition. The optimum concentration of Eu³⁺ in this host is found to be 4 mol% and the concentration quenching phenomenon is attributed due to dipole-dipole interaction of neighbouring Eu³⁺ ions. The calculated CIE coordinates of the prepared phosphors are similar to the NTSC red phosphor and commercial red phosphors. These results suggests that the Sr₂CaTeO₆:Eu³⁺ phosphors are potential candidate to incorporate in WLEDs as an excellent red emitting phosphor.