Additive engineering has been regarded as a valuable approach for enhancing the power conversion efficiencies (PCEs) of organic solar cells (OSCs). However, the effective solid additive molecules, especially electron-deficient building blocks, that enhance the PCEs of OSCs are still limited. Herein, two cyano-functionalized highly electron-deficient building blocks, namely 3,6-dibromopyrazine-2-carbonitrile (CNPz) and 3,6-dibromopyrazine-2,5-dicarbonitrile (DCNPz), which feature simple structures and facile synthesis are employed as solid additives to optimize the performance of OSCs. It is found that CNPz can modulate the intermolecular interactions and improve the molecular packing, which is beneficial for charge generation, transport, and collection. As a result, a 19.67% PCE is achieved in the PTQ10/m-BTP-PhC6 binary devices, ranking amongst the highest values for OSCs. Furthermore, the general applicability of solid additives is demonstrated in other organic photovoltaic systems. These findings offer valuable insights into designing and developing novel electron-deficient solid additives to boost the efficiency of OSCs.

中文翻译：

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氰基官能化吡嗪：作为固体添加剂的缺电子单元使二元有机太阳能电池的效率达到 19.67%

增材工程被认为是提高有机太阳能电池（OSC）功率转换效率（PCE）的一种有价值的方法。然而，能够增强OSCs PCE的有效固体添加剂分子，特别是缺电子构件仍然有限。本文中，两种氰基功能化的高缺电子结构单元，即3,6-二溴吡嗪-2-甲腈（CNPz）和3,6-二溴吡嗪-2,5-二甲腈（DCNPz），具有结构简单、合成容易的特点。用作固体添加剂以优化OSC的性能。研究发现CNPz可以调节分子间相互作用并改善分子堆积，有利于电荷的产生、传输和收集。结果，PTQ10/ m -BTP-PhC6 二元器件实现了 19.67% 的 PCE，位居 OSC 的最高值之​​列。此外，固体添加剂的普遍适用性在其他有机光伏系统中得到了证明。这些发现为设计和开发新型缺电子固体添加剂以提高 OSC 的效率提供了宝贵的见解。