We develop an external-electric-field (EEF)-assisted annealing treatment to improve the photoelectric performance of planar organic–inorganic perovskite solar cells (PSCs). The new strategy can control the ion polarization orientation of perovskite films to obtain a good crystallization film and enhance the built-in electric field (BIF), which facilitates the effective promotion of charge separation and transport. Under an optimized treatment of up-EEF-assisted (2.5 V μm⁻¹) annealing, the power conversion efficiency (PCE) of the inverted PSC is improved from 15.33% to 17.26%, and from 16.77% to 19.18% for regular PSCs, compared with the thermal-annealing-only process. The ion polarization and ferroelectricity in the perovskite layer induced by the EEF are intensively discussed. The finding in this work provides a new route to improve perovskite film quality and cell performance.

中文翻译：

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电场辅助钙钛矿结晶，用于高性能太阳能电池†

我们开发了外部电场（EEF）辅助退火处理，以改善平面有机-无机钙钛矿太阳能电池（PSC）的光电性能。该新策略可以控制钙钛矿薄膜的离子极化取向，以获得良好的结晶薄膜，并增强内置电场（BIF），从而有助于有效促进电荷的分离和迁移。经过优化的上电势辅助（2.5 Vμm- ¹）退火后，与常规的仅进行热退火的过程相比，倒置PSC的功率转换效率（PCE）从15.33％提高到17.26％，而常规PSC的功率转换效率从16.77％提高到19.18％。深入讨论了由EEF引起的钙钛矿层中的离子极化和铁电性。这项工作的发现为改善钙钛矿薄膜的质量和电池性能提供了一条新途径。