Facile synthesis strategy for cesium tin halide perovskite crystals toward light emitting devices and anti-counterfeiting flexible fiber

Abstract

All-inorganic metal halide perovskites are widely studied because of their excellent photoelectric properties. However, due to the toxicity of CsPbX₃ (X = Cl, Br, I) perovskites, it is difficult to apply them on a large scale. The lead-free nature and air stability make Cs₂SnX₆ (X = Cl, Br, I) perovskites possible candidates to replace CsPbX₃ perovskites. Herein, we report the perovskite crystals (PCs) based on Te(IV)-doped Cs₂SnCl₆: Cs₂Sn_1−xTe_xCl₆. Cs₂Sn_1−xTe_xCl₆ PCs showed yellow emission under a 365 nm ultraviolet lamp. The photoluminescence quantum yield (PLQY) of Cs₂Sn_0.94Te_0.06Cl₆ PCs was 57.09%, which was proposed to be from the triplet Te(IV) ion ³P₁ → ¹S₀ self-trapping excitons (STE) recombination. The perovskite crystals can be used to fabricate light-emitting diodes (LEDs). The fiber paper prepared from aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS) fibers showed a bright yellow light under 365 nm ultraviolet light after being post-processed with Cs₂Sn_1−xTe_xCl₆ PCs solution. The ACFs/PPS compound fiber paper modified with Cs₂Sn_1−xTe_xCl₆ PCs maintained exceptional optical properties and could be stored in air for more than 4500 h. The fluorescence performance of the modified ACFs/PPS compound fiber paper could be applied to fluorescence anti-counterfeiting. The modification strategy and the applications in this work will provide a good choice for studying the optical performance of perovskites and broaden the application of ACFs/PPS compound fiber paper.