Balance of the Luminous Efficiency and Charge Transport by Incorporating AIE Unit for High‐Performance Organic Solar Cells with Low Non‐Radiative Energy Loss
Junjie Wang, Tong Liu, Yetai Cheng, Cheng Sun, Xiaolin Jiang, Jinyang Zhao, Yunpeng Li, Shian Ying, Yuchao Liu, Yuchao Liu, Hao Lu, Yahui Liu, Zhishan Bo, Xichang Bao, Shouke Yan, Xichang Bao, Shouke Yan
Abstract
Abstract Minimization of energy loss ( E loss ) is crucial for enhancing power conversion efficiencies (PCEs), especially the open‐circuit voltages ( V OC s) in organic solar cells (OSCs) as tight aggregation of conjugated materials often causes fluorescence quenching, leading to excessive non‐radiative loss (Δ E nr ). Herein, the effects of two strategies are systematically investigated for introducing high‐luminescent tetraphenylethylene (TPE) groups with aggregation‐induced emission characteristics on reducing Δ E nr and improving device performance. The two strategies involve, respectively, incorporating TPE‐Br as an additive to binary OSCs via simple physical blending, and synthesizing a new BTP‐TPE acceptor as the guest component by chemically bonding TPE units. The D18:L8BO:TPE‐Br OSC achieves a PCE exceeding 19%. Remarkably, D18:BTP‐TPE OSC attains the lowest reported Δ E nr to date. Furthermore, adding BTP‐TPE to D18:L8BO OSC yields an outstanding PCE over 20%, achieving the minimum Δ E nr and the maximum V OC among all reported OSCs with PCEs exceeding 20%. A comprehensive analysis demonstrates that the introduction of BTP‐TPE effectively optimizes the luminescence and charge transport and further indicates a revolutionary strategy to inhibit Δ E nr . This work emphasizes the potential of AIE groups in inhibiting Δ E nr and provides new insights for achieving low E loss and high‐performance OSCs by integrating photovoltaic and luminous performance into single molecule.