Spatially resolved power conversion efficiency for perovskite solar cells via bias-dependent photoluminescence imaging

Hybrid organic-inorganic perovskite solar cells (PSCs) offer a highly promising solution for achieving low-cost, high-performance photovoltaics. However, to accelerate the development of the PSC technology, it is critical to quantify local performance losses and identify problematic regions across the device. Obtaining spatially resolved information is essential not only for device fabrication but also for material optimization, particularly when scaling up the perovskite technology. In this work, we propose an imaging-based approach to spatially resolve local series resistance, power conversion efficiency (PCE), and charge-transfer efficiency across PSCs by employing bias-dependent photoluminescence (PL). By analyzing these parameters' images, we find a significant correlation between the charge-transfer efficiency and the PCE. However, we observe a weak correlation between the intensity of the PL image taken under open-circuit conditions and the final PCE of the device. This finding highlights the risk of misinterpreting the device performance if using only PL intensities. Moreover, we demonstrate the impact of the voltage-dependent series resistance on the accuracy of the device simulation. This work presents another important contribution of luminescence imaging to the research and development of the perovskite solar cells technology.