Luminescent properties of Sr2.5−3x/2Ba0.5SmxAlO4F oxyfluorides

► Under the excitation of 408 nm competent orange emitting Sr2.5−3x/2Ba0.5SmxAlO4F phosphor is initiated. ► Sm3+-activated oxyfluoride phosphor is quite effective to prepare white-emitting light for near-UV LED applications. ► Defects could be visibly created in the Sr2.5−3x/2Ba0.5SmxAl O4F host lattices when Sm3+ ions are doped less than 5 mol %. ► The gradual substitution of Sm3+ contents in oxyfluoride hosts is amenable to change CIE values and desired emitting intensity.