A well-developed perovskite crystal at the beginning of a crystal lattice facilitates favourable growth orientation for efficient charge transport and the elimination of buried interfaces. However, rapid and uncontrollable crystallization of perovskites poses significant challenges in achieving desired growth orientations and controlling the growth direction during crystallization, necessitating the establishment of optimal substrate conditions. In this study, we propose a bidirectional coordination strategy involving the introduction of cesium trifluoroacetate (CsTFA) onto a tin dioxide (SnO₂) surface. Treatment with CsTFA facilitates the passivation of SnO₂ vacancies via COOH–Sn while concurrently forming intermolecular interactions with overlying perovskite crystals, manifested as CF₃⋯H–N for formamidinium (FA⁺) and CF₃⋯I–Pb, respectively. These interactions initiate the well-established beginning of the perovskite crystals and promote their vertical growth. Consequently, vertically grown perovskite crystals exhibit reduced tensile strain and fewer crystalline defects. Furthermore, a benign buried interface between the perovskite and underlying SnO₂ mitigates detrimental damage, thereby suppressing non-radiative recombination losses. This synergetic bidirectional coordination contributes to the fabrication of perovskite solar cells with a maximum power conversion efficiency of 25.60% (certified at 25.39%) and long-term stability under light illumination.

中文翻译：

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利用双向配位体构建有序晶体取向，实现高效稳定的钙钛矿太阳能电池


晶格起始处发育良好的钙钛矿晶体有利于有利的生长方向，从而实现有效的电荷传输和消除埋入界面。然而，钙钛矿的快速且不可控的结晶对实现所需的生长方向和在结晶过程中控制生长方向提出了重大挑战，因此需要建立最佳的衬底条件。在这项研究中，我们提出了一种双向配位策略，涉及将三氟乙酸铯（CsTFA）引入二氧化锡（SnO ₂ ）表面。 CsTFA 处理有助于通过 COOH-Sn 钝化 SnO ₂ 空位，同时与上面的钙钛矿晶体形成分子间相互作用，对于甲脒来说表现为 CF ₃ ⋯H-N（FA ⁺ ) 和 CF ₃ ⋯I–Pb 分别。这些相互作用启动了钙钛矿晶体的成熟开始并促进其垂直生长。因此，垂直生长的钙钛矿晶体表现出较小的拉伸应变和较少的晶体缺陷。此外，钙钛矿和下面的 SnO ₂ 之间的良性埋入界面减轻了有害损伤，从而抑制了非辐射复合损失。这种协同双向协调有助于钙钛矿太阳能电池的制造，其最大功率转换效率为25.60%（认证为25.39%），并且在光照下具有长期稳定性。