Na2CaSiO4:Eu3+-deep red-emitting phosphors with intense 5D0→7F4 transition

► The samples Na2−xCa1−xEuxSiO4 show an abnormally high intensity at about 703 nm from 5D0→7F4 transition of Eu3+ irons. ► Sample Na1.89Ca0.89Eu0.11SiO4 show deep red-emitting and high color purity with chromaticity coordinates (0.639, 0.359). ► Sample Na1.89Ca0.89Eu0.11SiO4 can serve as a potential red LEDs phosphor and light-converting material candidate used in silicon solar cells.