The power conversion efficiencies (PCEs) of inverted perovskite solar cells (PSCs) have been demonstrated to exceed 26%. However, the uncontrolled crystallization process negatively affects the film quality, consequently limiting the overall performance of PSCs. To address these issues, we propose a novel heterogeneous seed-assisted strategy for FAPbI₃ crystallization to regulate the crystallization process and enhance the α-phase perovskite formation. In this strategy, the strong interactions between 2,4-diaminopyrimidine (DAP) and perovskite species inhibit the solvent-dominated intermediate phase formation and promote the formation of DAP-FA⁺[PbI₃]⁻ (δ) heterogeneous seeds. These seeds rapidly transform into the desired α-phase during the initial formation stage, assisting the subsequent crystallization process. Consequently, a highly crystalline α-FAPbI₃ film is obtained with reduced trap density and increased carrier lifetime, leading to an impressive PCE of up to 25.29% along with upgraded stability for inverted devices. Our findings provide valuable insights into innovative utilization of heterogeneous seeds for depositing high-quality α-FAPbI₃ films.

中文翻译：

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异质种子辅助 FAPbI3 结晶用于高效倒置钙钛矿太阳能电池


倒置钙钛矿太阳能电池 (PSC) 的功率转换效率 (PCE) 已被证明超过 26%。然而，不受控制的结晶过程会对薄膜质量产生负面影响，从而限制 PSC 的整体性能。为了解决这些问题，我们提出了一种新颖的异质种子辅助 FAPbI ₃ 结晶策略，以调节结晶过程并增强 α 相钙钛矿的形成。在该策略中，2,4-二氨基嘧啶（DAP）和钙钛矿物质之间的强相互作用抑制了溶剂主导的中间相的形成并促进了 DAP-FA ⁺ [PbI ₃ ] ⁻ (δ) 异质种子。这些晶种在初始形成阶段迅速转变为所需的α相，有助于随后的结晶过程。因此，获得了高度结晶的 α-FAPbI ₃ 薄膜，其陷阱密度降低，载流子寿命增加，导致令人印象深刻的 PCE 高达 25.29%，同时提高了倒置器件的稳定性。我们的研究结果为创新利用异质种子沉积高质量 α-FAPbI ₃ 薄膜提供了宝贵的见解。