Spatially resolved photoluminescence (PL) and electroluminescence (EL) imaging technologies play a crucial role in evaluating the performance and stability of photovoltaic devices. However, their application in perovskite devices presents unique challenges. In this study, we report a discrepancy between the electrical performance of perovskite solar modules (PSMs) and the EL images. Following the application of a reverse bias voltage, we observed an increase in EL brightness associated with prolonged carrier lifetime and transport length. Furthermore, cross-sectional Kelvin probe force microscopy identified a significant potential increase primarily at the electron-transport layer (ETL) side after reverse bias, suggesting the presence of defective ETL/perovskite interfaces with filled hole traps. To address this EL mismatch, we proposed a mild reverse current recovery method aimed at aligning EL images with the cell performance without compromising device efficiency. This approach effectively mitigates discrepancies, ensuring alignment between the device performance and EL imaging. Our study underscores that caution is required when utilizing EL imaging to monitor spatial homogeneity in PSMs for future industrial production.

中文翻译：

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钙钛矿模块的反常电致发光特性


空间分辨光致发光（PL）和电致发光（EL）成像技术在评估光伏器件的性能和稳定性方面发挥着至关重要的作用。然而，它们在钙钛矿器件中的应用提出了独特的挑战。在这项研究中，我们报告了钙钛矿太阳能模块 (PSM) 的电气性能与 EL 图像之间的差异。应用反向偏压后，我们观察到 EL 亮度的增加与载流子寿命和传输长度的延长相关。此外，横截面开尔文探针力显微镜发现反向偏压后主要在电子传输层（ETL）侧电势显着增加，表明存在缺陷的 ETL/钙钛矿界面和填充的空穴陷阱。为了解决这种 EL 不匹配问题，我们提出了一种温和的反向电流恢复方法，旨在将 EL 图像与电池性能对齐，而不影响器件效率。这种方法有效地减少了差异，确保设备性能和 EL 成像之间的一致性。我们的研究强调，在利用 EL 成像来监测未来工业生产中 PSM 的空间均匀性时需要谨慎。