Reversible Switching of 0D Halide Perovskite with Small Molecule Absorbate for Information Encryption

Abstract Organic–inorganic metal halide framework has provided a novel material platform with explicit functionality in terms of light emitting properties. However, coexistence of high efficacy, sensitivity, along with stability is rare. Herein, a class of 0D perovskite material (BAPP)In _2‐2x Sb _2x Br ₁₀ (where BAPP is (1,4‐bis(3‐aminopropyl) piperazine) is presented simultaneously featuring strong fluorescence and advanced optical characteristics. In addition to its inquisitive property, a reversible solid‐state photoluminescence transition triggering is portrayed on the addition of a small foreign molecule like methanol. The reversible transition is accompanied by quenching the overall emission of the doped material with considerable modification in the mother structure. These switchable on‐off transitions are accompanied by the attachment of a methanol group to the octahedral centers. Furthermore, these switchable emission states are utilized for an efficient information encryption strategy through an 8*8‐bit ASCII code in the form of a modular matrix. Hence, such mechanistic investigations with respect to photoluminescence (PL) modulations provide new avenues for unclonable information storage and encryption for diverse fields.