Orange-reddish emitting of trivalent samarium doped double perovskite Sr2LuNbO6 with high thermal stability for white-LED application

A series of trivalent samarium ions (Sm3+) doped double perovskite Sr2LuNbO6 (x at% Sm3+:Sr2LuNbO6, x = 0.5–15) phosphors have been prepared via high-temperature solid-state method. The structural characterization of these phosphors was conducted employing X-ray diffraction (XRD), XRD Rietveld refinement, scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. Density functional theory calculations utilizing the Vienna ab initio simulation package (VASP) were employed to unveil the electronic structures, encompassing the band structure and density of states (DOS). Photoluminescence (PL) spectroscopy was employed to scrutinize the luminescent properties, while the thermal stability of the PL spectra was also evaluated. The most prominent emission peak, exhibiting an orange-reddish hue, was observed at 601 nm upon excitation at 406 nm. The quenching mechanism of Sm3+ ions within the Sr2LuNbO6 host lattice was identified as a dipole-dipole interaction, with the quenching concentration of 3 at%. Moreover, the phosphors demonstrated excellent thermal stability, with an activation energy (Ea) value of 0.126 eV. These findings collectively underscore the promising potential of Sm3+:Sr2LuNbO6 orange-reddish phosphors for applications in white light-emitting diodes (w-LEDs).