Quasi‐2D Ruddlesden–Popper (RP) perovskite solar cells (PSCs) have drawn significant attention due to their appealing environmental stability compared to their 3D counterparts. However, the relatively low power conversion efficiency (PCE) greatly limits their applications. Here, high photovoltaic performance is demonstrated for quasi‐2D RP PSCs using 2‐thiophenemethylammonium as spacer with nominal n‐value of 5, which is based on the stoichiometry of the precursors. The incorporation of formamidinium (FA) in quasi‐2D RP perovskites reduces the bandgap and improves the light absorption ability, resulting in enlarged photocurrent and an increased PCE of 16.18%, which is higher than that of reported analogous methylammonium (MA)‐based quasi‐2D PSC (≈15%). A record high PCE of 19.06% is further demonstrated by using an organic salt, namely, 4‐(trifluoromethyl)benzylammonium iodide, assisted crystal growth (OACG) technique, which can induce the crystal growth and orientation, tune the surface energy levels, and suppress the charge recombination losses. More importantly, the devices based on OACG‐processed quasi‐2D RP perovskites show remarkable environmental stability and thermal stability, for example, the PCE retaining ≈96% of its initial value after storage at 80 °C for 576 h, while only ≈37% of the original efficiency left for FAPbI₃‐based

中文翻译：

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有机盐辅助晶体生长和准2D Ruddlesden-Popper钙钛矿用于太阳能电池的效率超过19。

准2D Ruddlesden-Popper（RP）钙钛矿太阳能电池（PSC）由于其与3D同类产品相比具有吸引人的环境稳定性而备受关注。但是，相对较低的功率转换效率（PCE）极大地限制了它们的应用。在此，以2-噻吩甲基铵为间隔物并标称n的准2D RP PSC展示了高光伏性能-值为5，基于前体的化学计量。在准2D RP钙钛矿中掺入甲酰胺（FA）可以降低带隙并提高光吸收能力，从而导致光电流增大和PCE增加16.18％，高于已报道的类似基于甲基铵（MA）的准钙钛矿‐2D PSC（≈15％）。通过使用有机盐即4-（三氟甲基）苄基碘化铵，辅助晶体生长（OACG）技术进一步证明了PCE达到创纪录的19.06％的高水平，该技术可以诱导晶体生长和取向，调节表面能级以及抑制电荷复合损失。更重要的是，基于OACG处理的准2D RP钙钛矿的设备具有出色的环境稳定性和热稳定性，例如，基于₃