Stress‐Induced Multi‐Stimulus‐Responsive Mechanoluminescence in Mn2+ Doped Double Perovskite Compound

Abstract

AbstractMulti‐mode mechanoluminescence (ML) materials are have applications such as anti‐counterfeiting, stress sensing, and information security. There is limited general consensuses on the luminescent mechanisms, even though exploring ML mechanism based on defects has shown significance in further studies exploring both ML materials design and application. Here, a deep‐red to near‐infrared (NIR) ML material is reported in a Mn2+‐activated double perovskite‐type compound (CaZnGe2O6: Mn2+). The abundant lattice sites within the crystal structure have enabled Mn2+ doping and defects. Two different photoluminescence (PL) emission bands peaked at 536 and 676 nm from 4T1(4G)→6A1(6S) are observed, which are attributed to the substitution of Zn2+ and Ca2+ sites by Mn2+, respectively. Hence, tunable emissions from green to red are realized in single Mn2+ doping, which can be further regulated by varying the Mn2+ concentration. Electrons and holes are captured by cation and anion defects ( and , , vacancy of Zn, Ca and O ions), followed by the combination of such carriers to transfer energy to the Mn2+ 3d states to produce ML/persistent luminescence (PersL) under mechanical/thermal stimuli. Proof‐of‐concept applications in multi‐mode anti‐counterfeiting, temperature sensing, and X‐ray imaging fields are demonstrated. These results will deepen the understanding of single Mn2+‐doped multi‐stimulus‐responsive ML materials, inspiring the development of more high‐performance ML phosphors for practical applications.