Persistence Luminescence and Mechanoluminescence in Er3+/Eu2+ Co-Doped SrS/SrZnSO Composites

A series of Er 3+ /Eu 2+ -activated SrS/SrZnSO with different Er 3+ /Eu 2+ concentrations were synthesized at 1300℃ for 3 h through high temperature solid-state reaction, and their persistence luminescence and mechanoluminescence properties were studied. Upon 450 nm laser excitation, SrS/SrZnSO:Er 3+ /Eu 2+ emitted orange-red light, which could be observed with the naked eyes. When the laser was removed, it showed long afterglow orange-red luminescence. The brightness and duration of the long afterglow increase with the increase concentration of Er 3+ /Eu 2+ from x:y = 0.5%:1% to 3%:1%. SrS/SrZnSO:Er 3+ /Eu 2+ was confirmed as an excellent persistent luminescence material since it could continuously emit light for nearly 10 min. Moreover, under pressure stimulation SrS/SrZnSO:Er 3+ /Eu 2+ showed a novel type of mechanoluminescence (ML) with the emitting bright green light which linearly depended on the force. Under the same force of friction, the sample SrS/SrZnSO:Er 3+ /Eu 2+ with Er 3+ /Eu 3  = 1%:0% emitted the strongest ML among prepared samples. Furthermore, the mechanism of mechanoluminescence was studied in details. This study can expand the family of ML materials while promoting the applications of mechanoluminescence materials in damage diagnosis, human-machine interfaces, and pressure sensing. Graphical