Tong Liu

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.