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

Abstract Multi‐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 Mn 2+ ‐activated double perovskite‐type compound (CaZnGe 2 O 6 : Mn 2+ ). The abundant lattice sites within the crystal structure have enabled Mn 2+ doping and defects. Two different photoluminescence (PL) emission bands peaked at 536 and 676 nm from 4 T 1 ( 4 G)→ 6 A 1 ( 6 S) are observed, which are attributed to the substitution of Zn 2+ and Ca 2+ sites by Mn 2+ , respectively. Hence, tunable emissions from green to red are realized in single Mn 2+ doping, which can be further regulated by varying the Mn 2+ 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 Mn 2+ 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 Mn 2+ ‐doped multi‐stimulus‐responsive ML materials, inspiring the development of more high‐performance ML phosphors for practical applications.