Holistic Anode Interface Engineering for High‐Efficiency and Stable Carbon‐Perovskite Solar Modules

ABSTRACT Achieving a simultaneous balance of cost, efficiency, and operational stability is critical for the commercial viability of perovskite photovoltaics. Planar‐junction carbon‐based perovskite solar modules (C‐PSMs) represent a promising platform toward this goal, offering low‐cost fabrication and long‐term environmental stability enabled by thick carbon electrodes that eliminate the need for encapsulation. However, their power conversion efficiency remains fundamentally limited due to the discontinuous charge percolation and poor heterojunction contact at the carbon/perovskite junction. To overcome these challenges, we present a Holistic Anode Interface Design (H‐AID) strategy that integrates two complementary approaches. First, a picosecond laser is used to sculpt a curved perovskite surface morphology, increasing contact area and enhancing charge transfer (Design‐1). Second, a gallium‐indium eutectic liquid metal is introduced into the carbon paste to fill internal voids and restore conductive pathways (Design‐2). Their combination (Design‐3) achieves a 42% improvement in module efficiency, reaching 16.88% over a 61.22 cm 2 active area, among the highest reported for planar C‐PSMs. Moreover, the device retains over 95% of its initial performance after 1200 h under ambient, encapsulated conditions. This work establishes a scalable H‐AID framework to unlock cost‐efficiency‐stability co‐optimization in carbon perovskite modules.