Air-scalable blue perovskite luminescent filaments with ultra-high stability and multifunctional applications

Abstract

Lead-halide perovskites have emerged as promising luminescent materials for smart wearable optoelectronics. However, blue-emitting perovskites, an indispensable component of the RGB tricolor, suffer from poor stability, and their scalable ambient fabrication remains a significant challenge. To address this issue, we report a series of high-stability blue CsPb(Cl_xBr_1-x)₃ (x = 0.3∼0.7) perovskite luminescent filaments (Cl_xBr_1-x PLFs) constructed in ambient air via an eco-friendly wet-spinning process. This highly sustainable and cost-effective technology (water coagulation bath, $0.3 per 100 m, ∼100% precursor utilization, length ∼30 m) yields the blue Cl_0.5Br_0.5 PLF with high luminescent brightness, prominent stability, and large stretchability (ε∼1700%). Notably, the thermoplastic polyurethane (TPU)’s backbone effect, physical blocking, in situ encapsulation, and chelation with perovskite collectively endow Cl_0.5Br_0.5 PLF with superior long-term stability upon ambient air/high humidity/water (> 40 days), thermal aging, continuous light irradiation, and diverse solutions. The initial photoluminescence enhancement upon humidity/water is ascribed to improved crystallization, reduced trap-assisted recombination, and increased radiative recombination, which is enabled by the unique size-selective permeation property of TPU. Benefiting from its attractive optical and mechanical properties and seamless textile-integrability, the blue PLFs provide broad application prospects in hazard warning, flexible displays, sensors, dual-level information encryption, and secondary anti-counterfeiting.