Tandem organic solar cells with 20.6% efficiency enabled by reduced voltage losses

作者：Jianqiu Wang, Zhong Zheng, Pengqing Bi, Zhihao Chen, Yafei Wang, Xiaoyu Liu, Shaoqing Zhang, Xiaotao Hao, Maojie Zhang, Yongfang Li, Jianhui Hou · 发表于：National Science Review · 年份：2023 · DOI：10.1093/nsr/nwad085 · 被引用次数：209 · 研究领域：Organic Electronics and Photovoltaics、Perovskite Materials and Applications、Conducting polymers and applications

Large voltage losses are the main obstacle for achieving high efficiency in organic solar cells (OSCs). Here we construct ternary OSCs by introducing an asymmetric small molecule acceptor AITC into PBDB-TCl : BTP-eC9 system and demonstrate the effectiveness in simultaneously decreasing energy disorder and non-radiative voltage losses. It is found that the introduction of AITC can modify domain size and increase the degree of crystallinity, which enhances open-circuit voltage and power conversion efficiency (19.1%, certified as 18.9%). Inspiringly, an output efficiency of 20.6% of the constructed tandem OSCs based on PBDB-TCl : AITC : BTP-eC9 ternary active layer output a recorded efficiency of 20.6% (certified as 20.3%), which is the highest value in OSCs field to date. This work demonstrates that decreasing the voltage losses by ternary strategy and constructing of tandem architecture are effective approaches towards improving photovoltaic performance.