Luminous tuning in Eu3+/Mn4+ co-doped double perovskite structure by designing the site-occupancy strategy for solid-state lighting and optical temperature sensing

Abstract

Currently, Eu3+ or Mn4+ activated red-emitting fluorescent materials are widely used for solid-state lighting and optical temperature sensing. Here, we have chosen an abundant double perovskite structure that provides not only a trivalent Eu3+ lattice but also a tetravalent Mn4+ lattice and guarantees simultaneous emission. A family of rare earth (Eu3+) and transition metal (Mn4+) co-doped La3Li3W2O12 (LLWO) red-emitting phosphors were obtained by designing a site-occupation strategy. By changing the concentration of Eu3+, the coordination environment of the activator is adjusted to finally achieve the adjustable emission of the phosphor from orange to red. In addition, when the doping concentration of Eu3+ is greater than 0.05, the symmetry of the doping sites in the perovskite structure decreases leading to the luminescence performance of red color and the enhancement of luminescence intensity. Finally, optical thermometry based on fluorescence intensity ratio shows that the developed phosphor has high sensitivity.