Perovskite solar cells (PSCs) have attracted significant attention owing to their prominent photovoltaic (PV) performance. Their multi-layered structure facilitates efficient charge separation in i-type-like perovskite photoabsorbers when sandwiched with a p-type hole transport material (HTM) and n-type electron transport material (i.e., n-i-p or p-i-n structures), enabling high PV performance. Since heterointerfaces are prone to creating defects that act as carrier traps, modulating them in PSCs is crucial. In this review, the nascent yet potent spontaneous heterointerface modulation techniques, and effectiveness of spontaneous heterointerface modulators (SHMs) are highlighted. SHMs are used as additives for precursor solutions of PSC components (e.g., perovskite precursor solutions and HTM solutions) and can bypass the conventional treatment of heterointerface modulations; SHMs can increase process efficiencies of PSC fabrications. Additionally, SHMs can effectively modulate buried interfaces, reducing the risk of defect formation caused by atmospheric contamination. Furthermore, several SHMs serve additional benefits that the conventional step-by-step heterointerface modulation cannot attain. In particular, alkyl-primary-ammonium-based ionic liquids (RA-TFSIs), which are a novel series of ionic liquids designed for PSC applications and used as HTM additives, are highlighted. During the deposition of HTM solutions containing RA-TFSIs on perovskite layers, RA cations spontaneously passivate the perovskite layers, generating unique benefits, which can be tuned via the molecular structure of RA cations. In addition, emerging RA-TFSIs have shown promise beyond PSCs, as deviation of their components from the currently major ionic liquids opens avenues for diverse applications that have remained unexplored. Therefore, this review will guide further development of materials science.

中文翻译：

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用于钙钛矿太阳能电池的自发异质界面调制器

钙钛矿太阳能电池 （PSC） 因其突出的光伏 （PV） 性能而受到广泛关注。当与 p 型空穴传输材料 （HTM） 和 n 型电子传输材料（即 n-i-p 或 p-i-n 结构）夹在一起时，它们的多层结构有助于在类 i 型钙钛矿光吸收器中实现高效的电荷分离，从而实现高 PV 性能。由于异质界面容易产生充当载流子陷阱的缺陷，因此在 PSC 中调节它们至关重要。在这篇综述中，强调了新兴但有效的自发异质界面调节技术以及自发异质界面调节剂 （SHM） 的有效性。SHM 用作 PSC 组件前驱体溶液（例如钙钛矿前驱体溶液和 HTM 溶液）的添加剂，并且可以绕过异质界面调制的常规处理;SHM 可以提高 PSC 制造的工艺效率。此外，SHM 可以有效地调节埋地界面，降低大气污染导致缺陷形成的风险。此外，一些 SHM 还具有传统逐步异质界面调制无法实现的额外优势。特别强调了烷基伯铵基离子液体 （RA-TFSIs），这是专为 PSC 应用设计并用作 HTM 添加剂的新型离子液体系列。在钙钛矿层上沉积含有 RA-TFSI 的 HTM 溶液的过程中，RA 阳离子自发钝化钙钛矿层，产生独特的好处，这可以通过 RA 阳离子的分子结构进行调整。 此外，新兴的 RA-TFSI 已显示出超越 PSC 的前景，因为其成分与当前主要离子液体的偏差为尚未探索的各种应用开辟了途径。因此，本文将指导材料科学的进一步发展。