Intense-Light Sensing Yarns Achieved by Interfused Inorganic Halide Perovskite Nanofiber Network

Fully inorganic metal halide perovskites (MHPs) demonstrate enhanced stability over their organic–inorganic counterparts, however, their integrations into flexible or textile-based substrates remain a significant challenge, due to their inherent rigidity and the necessity of high-temperature annealing. Herein, we propose a one-step and near-room-temperature electrospinning process to fabricate flexible CsPbI₂Br nanofibers that can be directly deposited on the yarns. With the in-situ CsPbI₂Br crystallization during electrospinning, annealing-free and photoelectroactive γ-CsPbI₂Br can be achieved. Polyvinyl acetate (PVAc) serves as the carrier polymer to offer the flexibility and facilitate the chemical interaction with CsPbI₂Br, thereby mitigating moisture and oxygen-induced degradations. CsPbI₂Br-PVAc nanofibers obtained under the optimal electrospinning condition: high-electrospinning voltage (25 kV) and low-solution supply rate (0.02 mm/min), show more uniform morphology, increased stability, and extended photoluminescence decay time. These nanofibers enable the construction of photo-sensing yarn devices, capable of generating a photovoltage of around 180 mV and current density of 17 mA/cm² upon illumination by a 532 nm pulsed laser, while maintaining a remarkable ambient stability of 16 days. Given their laser-energy-dependent voltage output, these yarns hold significant potential for developing high-intensity light-detecting textiles for various applications.