Synthesis and luminescent properties of Na5La1−xEux(WO4)4 red phosphors

► Novel red emitting phosphors Na5La1−xEux(WO4)4 were synthesized. ► The phosphors were excited near 395 nm and showed no concentration quenching. ► The crystal structure and parameters were refined using the Rietveld method. ► The calculated quantum efficiency of Na5Eu(WO4)4 specimen is around 47%.