Novel PEI cross-linking strategy for improved conductivity and stability of AgNWs films in flexible electronics

Silver nanowires (AgNWs) have gained significant attention in the realm of flexible electronic devices due to their exceptional conductivity, stable mechanical properties, and chemical stability. Nonetheless, the inherent robustness and intricate post-processing techniques associated with AgNWs pose challenges to their further development. This study employed a novel polyethyleneimine (PEI) crosslinking strategy and incorporated water immersion as a post-treatment step, significantly enhancing the conductivity and stability of flexible electronic devices. Introducing PEI to form a large number of hydrogen bonds with polyvinylpyrrolidone (PVP) as a dispersant bridged the originally loose PVP molecular chains into a three-dimensional cross-linked network. The IP-AgNWs thin film, prepared via the Meyer stick scraping method, exhibited remarkable electrical properties, achieving a sheet resistance of 3.2 Ω/sq. After exposure to air for one month, the sheet resistance was increased minimally to 4 Ω/sq, indicating commendable durability. When the IP-AgNWs film was employed as a heater, it can reach to a maximum temperature of 94 °C under an applied voltage of 2.5 V, maintaining temperature stability for up to 1 h. Furthermore, IP AgNWs thin films demonstrated excellent electromagnetic shielding performance, achieving a shielding efficiency of up to 43 dB. These findings offer novel insights into the application of AgNWs conductive thin films in the domain of flexible electrodes.