Bright tunable luminescence of Sb³⁺ doping in zero-dimensional lead-free halide Cs₃ZnCl₅ perovskite crystals

Lead-free zero-dimensional (0D) perovskite nanocrystals (NCs) with isolated octahedral structures have attracted considerable attention due to their unique photoelectric properties, such as highly efficient emissions with broadband features. A series of phosphors composed of Sb³⁺-doped 0D perovskite crystals Cs₃ZnCl₅ with wavelength-tunable emission spectra have been obtained using a facile recrystallization method at room temperature in air. By controlling the doping concentration of Sb³⁺ in Cs₃ZnCl₅ lattice, bright emissions from red to orange have been achieved under excitation at 320 nm due to the expansion of the crystal lattice, and the emission excited at 275 nm is bluish-white, spanning the full visible region. Inductively coupled plasma emission spectrometry (ICP) demonstrates the Sb³⁺ substitutes for Zn²⁺ rather than Cs⁺ due to the similar charges and ionic radii. The luminescence performance of phosphor Cs₃ZnCl₅:Sb³⁺ can be improved obviously by replacing 3 mol% of Cs⁺ with Rb⁺ or K⁺ due to the further distortion of the crystal lattice. The present approach allows the synthesis of large-scale emissive lead-free 0D perovskites activated by Sb³⁺ with tunable luminescence color.