Structurally Tunable Lead‐Free Double Perovskite with Acid Resistance for Functional Luminescent Fabrics and High‐Performance Piezoelectric Devices

Abstract Lead‐free perovskite is widely studied in optics and optoelectronics due to its excellent optoelectronic properties. Herein, lead‐free perovskite crystals (PCs) doped with two distinct elements are reported. The doping strategy enhances the emission intensity of perovskite and adjusts its emission wavelength. The fluorescence lifetime of La‐doped perovskite is 4.08 ms. The yellow light‐emitting diode (LED) prepared from Te 4+ ‐doped perovskite has a color purity of up to 95.54%. The color temperature of the white LED prepared by perovskite is 5910 K. Moreover, aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS) composite fiber paper exhibits luminescent properties under ultraviolet (UV) light after modification with perovskite crystals. Luminescent fibers retains the original flexibility and exhibits good luminescent stability. After 48 h of exposure to various industrial simulated exhaust gases, no significant luminescence attenuation or quenching phenomena are observed in the luminescent fibers. In addition, the composite fibers modified with perovskite also exhibit piezoelectric properties. The maximum output voltages of perovskite‐modified piezoelectric fibers doped with La 3+ and Te 4+ are 150 V and 48 V, respectively. The research on perovskite flexible, functional fabrics has taken a significant step forward in the development of flexible wearable devices, textile inspection, and intelligent sensing.