A research team at UNIST has developed a cutting-edge modular artificial leaf that revolutionizes green hydrogen production technology for carbon neutrality. The innovative system mimics natural photosynthesis, generating hydrogen solely from sunlight and water without external power sources or carbon emissions. Published in Nature Communications, this breakthrough approach directly converts solar energy to hydrogen, reducing losses from electrical resistance and minimizing installation space. To overcome efficiency and scalability challenges in traditional systems, the team created high-performance perovskite-based photoelectrodes and UV-resistant electron transport layers assembled into a scalable 4x4 array. Achieving a solar-to-hydrogen conversion efficiency of 11.2%, surpassing the commercial viability threshold, the artificial leaf leverages chlorine-doped perovskite absorbers, UV-resistant layers, and NiFeCo catalysts for enhanced performance and stability. Prof. Jae Sung Lee highlights the module's efficiency exceeding 10% as a critical milestone for real-world applications. The device's durability is ensured through nickel foil and resin encapsulation, enabling 140 hours of continuous operation with 99% performance retention. This breakthrough signifies a significant step towards commercial deployment and paves the way for large-scale panels akin to photovoltaic modules.