Fig. 1: Design concept and material characterization.

a Schematic representation of the rational design of Cl⁻ or Cd²⁺ sites in the CsCdCl₃ crystal structure, occupied by (I) Br⁻ or (II) Sn²⁺ ions to disrupt local symmetry in the host framework and promote LPL, color and PLQY properties. Details: The design employs shadows and lighting to highlight the inherent CsCdCl₃ crystal structure was disrupted by activated Cl⁻ or Sn²⁺ ions, bringing out a dual positive performance improvement strategy. Rietveld refinements of the typical XRD patterns of b CsCdCl₃:0.8%Br and c CsCdCl₃:10%Sn. SEM image of d CsCdCl₃:0.8%Br and e CsCdCl₃:10%Sn, along with their corresponding elemental mapping images of Cs, Cd, Cl, Br and Sn. f Wet-chemistry method for the synthesis of CsCdCl₃:x%Br and CsCdCl₃:x%Sn all-inorganic perovskites.