Fully Roll‐to‐Roll Coated Large‐Area Perovskite Solar Modules on Indium‐Free Microgroove Substrates

ABSTRACT Perovskite photovoltaics offer a promising route to low‐cost, low‐carbon solar energy, but progress toward largescale deployment is limited by manufacturing scalability, stability, and dependence on scarce materials. We demonstrate fully roll‐to‐roll coated, large‐area back‐contact perovskite photovoltaic modules based on a microgroove architecture that removes the need for transparent conductors such as Indium Tin Oxide (ITO). Devices are continuously manufactured on flexible substrates using scalable embossing, vacuum deposition, solution printing, and encapsulation. Modules with active areas up to 48.2 cm 2 achieve record power conversion efficiencies exceeding 12.5 % and are further scaled to panels larger than 1000 cm 2 . The first comprehensive stability study of fully roll‐to‐roll coated perovskite modules is presented, including ISOS‐compliant accelerated ageing and up to five months of outdoor operation. Nanoscale x‐ray fluorescence tomography identifies key degradation pathways within the microgroove architecture. In addition to scalable fabrication, the architecture enables intrinsic bifaciality, improved angular response, and linear shading tolerance, enhancing real‐world energy yield and supporting sustainable largescale deployment beyond conventional photovoltaics.