A Universal Biomineralization‐Like Interfacial‐Confined Strategy Enables Practicable, Meter‐Scale, Transmittance‐Adjustable, Highly‐Ordered, Photothermal‐Capable, 2D Conducting Polymers

Abstract Conducting polymers (CPs) encompass various cutting‐edge fields owing to their combination of polymer and conducting properties. However, the mismatch between the polymer growth process and the carrier mobility design leads to poor material and device consistency, and insufficient long‐term device stability, thus hindering the practical application of CPs. Although 2D construction has been explored to address these challenges, it typically leads to materials instability and lacks methods for large‐scale synthesis, making it unsuitable for many application scenarios. Here a universal biomineralization‐like strategy relying on the joint impaction of hydrogen‐bond and gravity for large‐scale fabrication of 2D CPs is developed. As‐fabricated meter‐scale Polypyrrole films exhibit high orderliness and can be assembled into multilayers, allowing for adjustable thickness and transparency. Notably, these films demonstrate exceptional photothermal properties and remarkable long‐term stability, as their surface temperature can reach 140 °C when irradiated with an 808 nm laser at 0.7 W cm −2 , with almost no attenuation after 170 days. Furthermore, under sunlight, the temperature can reach nearly 100 °C, showcasing significant potential in smart building and energy management applications. Importantly, this strategy can be extended to the 2D design of numerous light organic compounds, thus opening up possibilities for their practical applications.