Highly variable STE luminescence is realized within a transparent crystal composed of antimony-doped double perovskite. By controlling excitation conditions, we achieve highly efficient white photoluminescence (quantum yield >97%), X-ray excited blue emission with long afterglow (duration >9 h), and self-reproducible violet-blue mechanoluminescence. We show that the excitation-mode-selective emission can be harnessed for multi-level data encryption and authentication technologies.
