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

•Designed dual-activators in double perovskite according to site-beneficial occupation principle.•Perovskite La3Li3W2O12 matrix contains abundant sites that suitable the doping of Mn4+ and Lanthanide.•Taking advantage of diverse thermal quenching between Mn4+ and Eu3+ ions for optical thermometry.