Synthesis of flexible AgNW@SnO2 core-shell networks for transparent EMI shielding and infrared stealth

Ultrathin SnO 2 shell deposited on AgNWs via spray-dip process forms stable core-shell mitigating bare AgNWs instability. • Ag-SnO 2 heterojunction enhances interfacial polarization loss, balancing 88% transparency (550 nm) and 25.2 dB EMI shielding. • Composite maintains function after 1000 bends (5 mm radius) and low IR emissivity ∼0.2 for passive thermal management. The rapid development of flexible and transparent electronic devices, such as wearable devices and smart windows, requires thin films with high optical transmittance, effective EMI shielding, and low infrared emissivity. Although silver nanowires (AgNWs) possess excellent electrical conductivity and optical transparency, their practical application is limited by poor environmental stability, especially under oxidative and sulfidizing conditions. To overcome this limitation, a transparent and flexible AgNW@SnO 2 core-shell film is developed through a scalable solution-based spray-dip process. The key novelty lies in directly spraying AgNW networks onto PET substrates, followed by simple solution dipping to form a SnO 2 -derived protective shell, avoiding vacuum deposition, high-temperature treatment, and complex multistep processing. The SnO 2 shell protects AgNWs from environmental degradation and forms Ag-SnO 2 heterointerfaces, which enhance interfacial polarization and electromagnetic wave attenuation. Under optimized conditions, the film exhibits 88% transmittance at 550 nm, an EMI shielding effectiveness of 25.2 dB, low infrared emissivity of approximately 0.2, excellent stability under elevated temperatures and H 2 S exposure, and mechanical durability after more than 1000 bending cycles. This work integrates process simplicity, environmental durability, transparent EMI shielding, infrared stealth, and mechanical flexibility in the AgNW@SnO 2 film, offering a low-cost and industrially compatible route for scalable transparent EMI shielding materials. Download: Download high-res image (128KB) Download: Download full-size image