Large‐Scale Perovskite Photovoltaics: Mitigating Defect Challenges in Upscaled Modules and Monolithic Tandem Cells

ABSTRACT Perovskite solar cells (PSCs) have achieved certified power conversion efficiencies (PCEs) exceeding 27% in small‐area laboratory devices (typically < 1 cm 2 ), demonstrating considerable potential for commercialization. However, transitioning from small‐area devices to upscaled modules invariably results in a significant reduction in both PCE and operational stability. This performance loss primarily originates from the complex crystallization dynamics and the cross‐scale coupling effects of defects intrinsic to large‐area fabrication processes. This review provides a systematic analysis of the formation mechanisms of defects in large‐area perovskite photovoltaic modules and full‐size perovskite‐silicon tandem cells. It specifically addresses the evolution of multi‐level defects, spanning from the atomic scale to the micrometer scale and further to the macroscopic scale. Building upon this mechanistic understanding, the review summarizes cross‐dimensional strategies for controlling these multi‐scale defects, encompassing compositional engineering, additive engineering, interface modification, and advanced process optimization. Finally, we present a forward‐looking perspective on key research directions aimed at overcoming the “efficiency‐stability‐cost” triangular balance that currently constrains the pathway to widespread industrialization.