The performance of polymer solar cells (PSCs) is commonly improved using additives or annealing treatment. However, these processes are accompanied by disadvantages, including poor reproducibility and stability. Herein, a molecular design strategy is proposed to obtain additive- and annealing-free PSCs. IDTOT2F containing two alkoxyl side chains at the central unit of the nonfullerene acceptor IDTT2F was developed. This molecular design results in excellent solubility in solutions, ordered molecular packing in films, slightly elevated energy levels, and a higher film absorption coefficient. Compared with its counterpart IDTT2F, its improved solubility provides an active layer with better morphology, its ordered molecular packing enhances the charge mobility in blend films, and its slightly elevated energy level furnishes a higher open-circuit voltage of devices. As a result, IDTOT2F-based devices display a maximum power conversion efficiency of 12.79%, which is one of the highest values reported for a PSC fabricated without any extra treatment.

中文翻译：

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高效聚合物太阳能电池具有增强的溶解度和有序堆积的非富勒烯受体

通常使用添加剂或退火处理来改善聚合物太阳能电池（PSC）的性能。但是，这些方法都具有缺点，包括重现性和稳定性差。在本文中，提出了一种分子设计策略来获得无添加剂和无退火的PSC。IDTOT2F含有在nonfullerene受体的中心单元中的两个烷氧基侧链IDTT2F被开发。这种分子设计可在溶液中实现出色的溶解性，薄膜中分子的有序堆积，能量水平略有提高以及更高的薄膜吸收系数。与对应的IDTT2F相比，其改善的溶解度为活性层提供了更好的形态，其有序的分子堆积提高了共混膜中的电荷迁移率，并且其略微提高的能级提供了更高的器件开路电压。结果，基于IDTOT2F的器件显示出12.79％的最大功率转换效率，这是未经任何处理即可制造的PSC的最高报告值之一。