Straightforward encapsulation of ultrastable CsPbBr3 PQDs and rare-earth emitters in zeolite for ratiometric temperature sensing and wet fingerprint recognition

Abstract

All-inorganic metal halide perovskite quantum dots (PQDs) hybrids with high stability, multi-model emission and responsive luminescence are of great importance for optical applications. Herein, a dual-emitting CsPbBr₃/Si-1:Eu³⁺ composite was successfully prepared by simultaneous encapsulation of CsPbBr₃ PQDs and EuBr₃ through a one-step thermal diffusion method. The partial destruction of five-membered rings in Silicalite-1 (Si-1) zeolite resulted from the PbBr₂ etching effect at high temperatures enhances the bonding formation between Eu³⁺ and Si-OH, leading to the grafting of Eu³⁺ onto Si-1 zeolite framework. The strongly confined CsPbBr₃ PQDs in CsPbBr₃/Si-1:Eu³⁺ exhibit ultrastable green-emission over 30 days of soaking in water. Particularly, the CsPbBr₃ PQDs and red-light Eu³⁺ emission center display distinct thermal quenching behaviors at elevated temperatures. So the CsPbBr₃/Si-1:Eu³⁺ composite can serve as an effective ratiometric thermometer using the fluorescence intensity ratio (FIR) technique, showing a high sensitivity of 3.4 % ℃^-1 at 54 ℃ and a temperature resolution of less than 0.2 ℃ in the range of 20-100 ℃. The water-stable CsPbBr₃/Si-1:Eu³⁺ composite is also suitable for wet fingerprint recognition. This work introduces a straightforward method for preparing dual-emissive CsPbBr₃/Si-1: Eu³⁺ composite for multimodal applications.