Synthesis and Sm2+/Sm3+ doping effects on photoluminescence properties of Sr4Al14O25

► Solid-state synthesis route promote Sr4Al14O25 phase formation. ► For samarium reduction in Sr4Al14O25 H2 gas is necessary. ► Photoluminescence of mixed-valence samarium-doped Sr4Al14O25. ► Well resolved emission of Sm3+ and Sm2+ under UV excitation.