Dual‐Mode Trap‐Assisted Tunable Full‐Color Mechanoluminescence of CsCdCl ₃ Perovskite

ABSTRACT

Mechanoluminescence (ML) enables the direct conversion of mechanical stimuli into light signals, with full‐color ML offering great potential in stress sensing, anti‐counterfeiting, encryption, and flexible displays. However, existing ML systems often suffer from limited color tunability, poor trap control, insufficient cycling stability, and unclear luminescence mechanisms. Herein, with CsCdCl ₃ perovskite as the matrix, blue, green, and red primary luminescence centers were constructed by doping with Pb ²⁺ , Sb ³⁺ , and Mn ²⁺ ions, respectively. Doping‐induced lattice distortion and defect regulation significantly enhance trap density and distribution, enabling trichromatic ML, photoluminescence, and persistent luminescence (PersL) within the single CsCdCl ₃ material. By adjusting the ratios of the three dopants, full‐color ML, photoluminescence, and PersL covering the entire visible spectrum are achieved. Piezoelectric force microscopy and thermoluminescence analyses reveal that the ML does not originate from the piezoelectric effect but is governed by trap carrier release, involving a dual‐mode synergistic mechanism: “force‐triboelectric‐trap release‐ML” and “force‐tribothermal‐trap release‐ML.” Furthermore, the material exhibits excellent cycling stability over 100 filling–release cycles. This work not only establishes a trap‐assisted dual‐mode ML mechanism in halide perovskites but also provides new insights for designing full‐color stress visualization, information encryption, and flexible optical sensing materials.