Antimony-doped enhanced photoluminescence quantum yield in zero-dimensional lead-free metal halide Rb2CsBiCl6 crystals

Zero-dimensional (0D) lead-free all-inorganic metal halides have emerged as next-generation photoluminescent (PL) materials in recent years because of their extraordinary PL properties, non-toxicity, and high stability. Herein, a green, high stability, all-inorganic Rb2CsBiCl6 single crystal with 0D structure was grown as a new PL material. Strikingly, using the antimony doping strategy, the broad yellow emission of Rb2CsBiCl6 was significantly enhanced due to the enhanced absorption in the UV region, and the PL quantum yield was increased from 1% to 45% at room temperature. Furthermore, the fluorescent mechanism was revealed by the combination of optical characterizations and first-principles calculations.