Efficient Perovskite Solar Modules with Minimized Nonradiative Recombination and Local Carrier Transport Losses

Perovskite solar cells (PSCs) have seen rapid advance in power conversion efficiencies (PCEs). However, the state-of-the-art PSCs still suffer from inhomogeneously distributed nonradiative recombination and carrier transport losses. Here, we report a promising evaluation strategy of combining the generalized optoelectronic reciprocity theorems and camera-based luminescence imaging techniques for PSCs. Excess lead chloride compositional engineering increases homogeneity and suppresses nonradiative recombination, leading to an external luminescence efficiency of 1.14% of devices (corresponding to a nonradiative voltage loss of 0.116 V). A favorable local and global carrier extraction property at maximum power point is also observed under moderate illumination level. As a result, we achieve a 25.49 cm2 perovskite solar module with a 17.88%-certified efficiency and a record fill factor over 78%. This quantitative and spatially resolved characterization is applicable at specific operating points, offering enormous potential for future real-time tracking of the lab-scaled devices and fast assessment of screening the large-area modules.