This article presents a breakthrough in perovskite solar cell technology by demonstrating one-year stable devices through the engineering of a 2D/3D perovskite interface. The study shows that a hybrid perovskite junction, composed of (HOOC(CH₂)₄NH₃)₂PbI₄ (2D) and CH₃NH₃PbI₃ (3D), achieves high efficiency and long-term stability. The 2D/3D interface provides enhanced stability and broad absorption, leading to efficiencies of 12.9% in a carbon-based architecture and 14.6% in standard mesoporous solar cells. The research also demonstrates the scalability of this technology, with the fabrication of 10×10 cm² solar modules using a fully printable industrial process, achieving 11.2% efficiency stable for over 10,000 hours. This innovation offers a low-cost, stable, and efficient solution for perovskite solar cells, paving the way for their commercialization. The study addresses the critical issue of stability in perovskite solar cells, which has been a major barrier to their market adoption. The 2D/3D interface engineering not only enhances the stability of the perovskite layers but also improves the overall performance and durability of the solar cells. The results highlight the potential of this approach for further device optimization and large-scale production.This article presents a breakthrough in perovskite solar cell technology by demonstrating one-year stable devices through the engineering of a 2D/3D perovskite interface. The study shows that a hybrid perovskite junction, composed of (HOOC(CH₂)₄NH₃)₂PbI₄ (2D) and CH₃NH₃PbI₃ (3D), achieves high efficiency and long-term stability. The 2D/3D interface provides enhanced stability and broad absorption, leading to efficiencies of 12.9% in a carbon-based architecture and 14.6% in standard mesoporous solar cells. The research also demonstrates the scalability of this technology, with the fabrication of 10×10 cm² solar modules using a fully printable industrial process, achieving 11.2% efficiency stable for over 10,000 hours. This innovation offers a low-cost, stable, and efficient solution for perovskite solar cells, paving the way for their commercialization. The study addresses the critical issue of stability in perovskite solar cells, which has been a major barrier to their market adoption. The 2D/3D interface engineering not only enhances the stability of the perovskite layers but also improves the overall performance and durability of the solar cells. The results highlight the potential of this approach for further device optimization and large-scale production.