Perovskite solar cells (PSCs) have made great research progress in the past decade. The interface behavior between the perovskite active layer (PAL) and hole transport layer (HTL) is one of the determinants of photovoltaic performance and stability of PSCs. Herein, we introduce a bifunctional modifier of 4-hydroxy-2,2,6,6-tetramethylpiperidine (HTMP) at the interface of PAL/HTL. The hydroxyl and imino groups in HTMP can interact with I and FA (MA) to form bi-directional hydrogen bonds to inhibit ion migration, reinforce the interface contact, and improve perovskite stability. On the other hand, the bifunctional groups of HTMP can passivate interface defects by coordinating with Pb²⁺, provide a more suitable energy gradient arrangement, and reduce nonradiative recombination loss. Compared to the efficiency of 19.05% obtained from the unmodified device, the HTMP-modified PSC achieves a maximum power conversion efficiency of 22.04%, along with a negligible hysteresis effect and good environmental stability, indicating that HTMP plays an excellent role in efficient and stable PSCs.

中文翻译：

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4-Hydroxy-2,2,6,6-tetramethylpiperidine 作为高效稳定钙钛矿太阳能电池的双功能界面改性剂

钙钛矿太阳能电池（PSC）在过去十年中取得了巨大的研究进展。钙钛矿活性层 (PAL) 和空穴传输层 (HTL) 之间的界面行为是决定 PSC 光伏性能和稳定性的因素之一。在此，我们在 PAL/HTL 界面引入了 4-羟基-2,2,6,6-四甲基哌啶 (HTMP) 的双功能改性剂。HTMP中的羟基和亚氨基可以与I和FA（MA）相互作用形成双向氢键，抑制离子迁移，加强界面接触，提高钙钛矿稳定性。另一方面，HTMP的双官能团可以通过与Pb ^{2+配位来钝化界面缺陷。}，提供更合适的能量梯度排列，减少非辐射复合损耗。与未改性器件获得的 19.05% 的效率相比，HTMP 改性的 PSC 实现了 22.04% 的最大功率转换效率，且滞后效应可忽略不计，环境稳定性良好，表明 HTMP 在高效稳定方面发挥了出色的作用。 PSC。