Seid Biruk Alebachew, Ozen Sercan, Castro-Méndez Andrés-Felipe, Neher Dieter, Stolterfoht Martin, Lang Felix
Physik und Optoelektronik weicher Materie, Institut für Physik und Astronomie, Universität Potsdam, 14476, Potsdam-Golm, Germany.
Electronic Engineering Department, The Chinese University of Hong Kong, Hong Kong SAR, 00000, China.
Adv Mater. 2025 Jul;37(30):e2501588. doi: 10.1002/adma.202501588. Epub 2025 May 9.
Bulky ammonium salt-based passivation is an effective strategy for enhancing the performance and stability of perovskite solar cells (PSCs). Especially, phenethylammonium iodide (PEAI) is known to greatly improve open-circuit voltage (V) and fill factor (FF). Despite these benefits, PEAI passivation leads to substantial short-circuit current density (J) losses and rapid degradation under operational conditions. In this work, it is revealed that the J loss as well as the accelerated degradation in PEAI-passivated devices is caused by an increased mobile ion density. To mitigate this performance and stability-limiting mechanism, ultrathin layers of ammonium benzenesulfonate (ABS) and/or ethylenediammonium diiodide (EDAI) salts are then introduced between the PEAI and the perovskite, which stabilize the 2D perovskite layer and impede diffusion even under upon prolonged illumination. This leads to a reduced mobile ion density both in fresh devices and in the long term, lowering losses J, and thus enables power conversion efficiencies of ≈25% with enhanced stability. Overall, this study not only addresses the limitations of PEAI-based 2D passivation but also paves the way for understanding 2D-induced ionic J losses.
基于 bulky 铵盐的钝化是提高钙钛矿太阳能电池（PSC）性能和稳定性的有效策略。特别是，已知苯乙铵碘化物（PEAI）能极大地提高开路电压（V）和填充因子（FF）。尽管有这些优点，但 PEAI 钝化会导致短路电流密度（J）大幅损失，并在工作条件下迅速降解。在这项工作中，揭示了 PEAI 钝化器件中的 J 损失以及加速降解是由移动离子密度增加引起的。为了减轻这种限制性能和稳定性的机制，然后在 PEAI 和钙钛矿之间引入超薄的苯磺酸铵（ABS）和/或乙二铵二碘化物（EDAI）盐层，即使在长时间光照下也能稳定二维钙钛矿层并阻碍扩散。这导致新器件和长期器件中的移动离子密度降低，降低了 J 损失，从而实现了约 25%的功率转换效率并提高了稳定性。总体而言，这项研究不仅解决了基于 PEAI 的二维钝化的局限性，还为理解二维诱导的离子 J 损失铺平了道路。
