The buried interface in inverted perovskite solar cells (PSCs) is critical for determining device performance. However, during annealing, the perovskite crystallized downward from the film’s top surfaces, and the use of dimethyl sulfoxide (DMSO) often resulted in voids at the perovskite bottom surface, which negatively impacted PSC performance. In this study, a green solid-state additive, piracetam (PA), was introduced into a perovskite precursor to reduce void formation. Due to the stronger interaction with perovskite components than DMSO, nonvolatile PA could remain within the perovskite films during thermal annealing to avoid volume collapse, thereby preventing the formation of voids at the buried interface as well as passivating the defects of undercoordinated Pb²⁺. Additionally, the introduction of PA could effectively enhance the crystallization of perovskite, leading to an improved quality of the perovskite films and depressed nonradiative recombination. As a result, the power conversion efficiency (PCE) of PSCs increased significantly from 20.95 to 23.42% with excellent operational and thermal stability.

中文翻译：

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高效稳定的倒置钙钛矿太阳能电池，通过绿色添加剂抑制空隙


倒置钙钛矿太阳能电池 （PSC） 中的埋入界面对于确定器件性能至关重要。然而，在退火过程中，钙钛矿从薄膜的顶表面向下结晶，并且使用二甲基亚砜 （DMSO） 通常会导致钙钛矿底面出现空隙，从而对 PSC 性能产生负面影响。在这项研究中，将绿色固态添加剂吡拉西坦 （PA） 引入钙钛矿前驱体中以减少空隙形成。由于与钙钛矿组件的相互作用比 DMSO 强，非挥发性 PA 在热退火过程中可以保留在钙钛矿薄膜内，以避免体积塌陷，从而防止在埋藏界面处形成空隙，并钝化配位不足的 Pb²⁺ 缺陷。此外，PA 的引入可以有效地增强钙钛矿的结晶，从而提高钙钛矿薄膜的质量并抑制非辐射复合。结果，PSC 的功率转换效率 （PCE） 从 20.95% 显著提高到 23.42%，具有出色的操作和热稳定性。