Precise Manipulation the Efficient Multi‐Exciton Emission with High Thermal Stability in Hybrid Manganese‐Antimony Chloride for Optical Thermometry, Anti‐Counterfeiting, and Information Encryption

Abstract Recently, zero‐dimensional (0D) metal halides with highly efficient tunable emission have shown broad prospects in the field of anti‐counterfeiting. However, the limited emission colors and low resolution, as well as the severe thermal quenching of self‐trapped excitons, have greatly constrained their applications. In this study, a high thermal stability compound by precisely manipulating the multi‐exciton emission within Sb‐doped hybrid manganese chloride is developed, which exhibits three emission colors (green, orange, and yellow). It is discovered that this compound exhibits significant color changes in the low‐temperature range. Optical temperature sensing, anti‐counterfeiting, and information encryption models based on this compound are successfully designed. This research proposes an effective strategy for designing novel eco‐friendly and efficient anti‐counterfeiting and temperature sensing materials, paving the way for optical temperature sensing and multi‐key encryption‐decryption applications.