A universal supramolecular assembly strategy for achieving efficient tunable white emission and anti-counterfeiting in antimony doped tin(iv)-based vacancy-ordered double perovskites

Abstract

Recently, Sb³⁺-doped all-inorganic vacancy-ordered double perovskites A₂SnCl₆ (A = K, Rb, and Cs) have attracted wide attention because of their unique optoelectronic properties and excellent stability. However, Sb³⁺-doped A₂SnCl₆ generally exhibits poor emission intensity. To overcome this, we take all-inorganic A₂SnCl₆ as the conformational model and utilize a universal supramolecular assembly strategy to develop three different halide perovskite materials with dumbbell structures of (KC)₂SnCl₆:Sb³⁺, (RbC)₂SnCl₆:Sb³⁺, and (CsC)₂SnCl₆:Sb³⁺ (C = 18-crown-6). While Sb³⁺-doped A₂SnCl₆ shows poor emission intensity, Sb³⁺-doped (AC)₂SnCl₆ exhibits efficient tunable white emission with a photoluminescence quantum yield (PLQY) of 86.7% for (KC)₂SnCl₆:Sb³⁺, 81.6% for (RbC)₂SnCl₆:Sb³⁺, and 89.8% for (CsC)₂SnCl₆:Sb³⁺, which stems from Sb³⁺-induced Jahn–Teller-like singlet and triplet self-trapped exciton (STE) emission. Particularly, the eruptive PLQY obtained in Sb³⁺-doped (AC)₂SnCl₆ can be attributed to the strong supramolecular interactions increasing the structural rigidity and thus inhibiting non-radiative transitions. Longer Sb–Sb distances in Sb³⁺-doped (AC)₂SnCl₆ facilitate the expression of Sb³⁺ 5s² lone pairs. Moreover, Sb³⁺-doped (AC)₂SnCl₆ also exhibits excellent chemical- and photo-stabilities. Finally, taking Sb³⁺-doped (KC)₂SnCl₆ as an example, we further demonstrated its applications in single-component white light-emitting diodes (WLEDs) at room temperature (RT), multiple-mode optical anti-counterfeiting, and information encryption.