Trap modification and mechanoluminescence improvement by Si substitution for Sn in Sr2SnO4:Sm3+ ceramics

A series of Sr 1 . 9 6 Sn 1 − x Si x O 4 :0.04Sm 3 + ( x = 0 , 0.1, 0.15, 0.2, 0.3, 0.4) were synthesized from solid-state reaction. The mechanoluminescence (ML) performance of Sr 1 . 9 6 SnO 4 :0.04Sm 3 + was greatly enhanced by partial Si 4 + substitution for Sn 4 + , and the sample of Sr 1 . 9 6 Sn 0 . 8 Si 0 . 2 O 4 :0.04Sm 3 + showed weaker afterglow and twice stronger ML intensity than that in Sr 1 . 9 6 SnO 4 :0.04Sm 3 + . The stress response of Sr 1 . 9 6 Sn 0 . 8 Si 0 . 2 O 4 :0.04Sm 3 + ranged from 250 to 1200 N, and its linearity was greatly restored. Particularly, it was very sensitive in the minimal stress response range. These properties of no load threshold for stress sensing and weak afterglow make Sr 1 . 9 6 Sn 0 . 8 Si 0 . 2 O 4 :0.04Sm 3 + superior to other excellent ML materials. The introduction of Si 4 + caused lattice distortion and promoted defect formation in the system. The trap level energy greatly increased and the trap depth changed, which enhanced the trap ability and therefore improved effectively the ML properties.