Passivation strategies are considered as one of the most efficient methods to suppress nonradiative recombination of organic–inorganic lead halide perovskite solar cells (PSCs), leading to tremendous photovoltaic performance. An innovative 2D polymer, graphitic carbon nitride (g‐C₃N₄), as well as various organic groups (amino, sulfonic, nitrato, and hydroxy group), are widely used as passivation agents, according to the previous reports. Anchoring g‐C₃N₄ and the aforementioned organic groups as additives in perovskite can both heal charged defects around the grain boundaries by passivating the charge recombination center. In addition, the crystalline quality can also be enhanced by the incorporation of g‐C₃N₄, leading to improved conductivity of perovskite light absorber films that is beneficial for benign charge extraction efficiency. Inspired by the underlining mechanisms, a series of novel passivation molecules, functionalized g‐C₃N₄ (F‐C₃N₄) with assorted organic groups, is designed herein, yielding a champion power conversion efficiency (PCE) of 20.08% for NO₃‐C₃N₄‐based p‐i‐n structure PSC, in comparison with that of PSC without passivation (17.85%). These findings present an efficient strategy to understand and design multiple facets of applications of novel passivation molecules to further improve the PCE of PSCs.

中文翻译：

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使用钙钛矿/表面改性的石墨化氮化碳异质结改善光伏性能

钝化策略被认为是抑制有机-无机卤化铅钙钛矿太阳能电池（PSC）非辐射复合的最有效方法之一，从而带来了出色的光伏性能。根据以前的报道，一种创新的二维聚合物，石墨碳氮化物（g-C ₃ N ₄）以及各种有机基团（氨基，磺酸，硝基和羟基）被广泛用作钝化剂。在钙钛矿中锚定g‐C ₃ N ₄和上述有机基团作为添加剂都可以通过钝化电荷复合中心来修复晶界周围的带电缺陷。此外，通过加入g‐C ₃ N也可以提高晶体质量_{如图4所示}，导致钙钛矿光吸收膜的电导率提高，这对于良性电荷提取效率是有利的。受下划线机制的启发，本文设计了一系列新颖的钝化分子，即具有各种有机基团的功能化g-C ₃ N ₄（FC-C ₃ N ₄），其产生的冠军功率转换效率（PCE）为20.08％与未钝化的PSC相比，NO _3‐ C ₃ N ₄基的P‐i‐n结构PSC（17.85％）。这些发现提出了一种有效的策略，以理解和设计新颖钝化分子应用的多个方面，以进一步改善PSC的PCE。