Shamrock‐Shaped Non‐fullerene Acceptors with Asymmetric End Groups Enable High‐Voltage and High‐Performance Organic Solar Cells

Comprehensive Summary Acenaphtho[1,2‐ b ]quinoxaline imide (AQI)‐based shamrock‐shaped non‐fullerene acceptors (NFAs) have garnered significant attention in the field of organic solar cells (OSCs) due to their high open‐circuit voltage ( V OC ) exceeding 0.95 V. Improving the short‐circuit current density ( J SC ) and fill factor (FF), while maintaining a high V OC , remains a pivotal challenge for this kind of emerging materials. Herein, three A'–DAD–A” type NFAs with asymmetric end‐group architecture, AQI13, AQI13‐b, and AQI13‐c, were developed, where IC‐2F was used as A' unit, and IC‐1F, NC‐1F and NC‐2F were utilized as A” units, respectively. The intermolecular packing mode is regulated through this end‐group modification strategy, thereby improving the J SC and FF. Meanwhile, a balance in the trade‐off relationship between J SC and V OC was established by modulating the intramolecular charge transfer (ICT) effect through asymmetric design. Consequently, the D18/AQI13, D18/AQI13‐b and D18/AQI13‐c layer‐by‐layer (LBL) devices demonstrate high PCEs of 17.78%, 17.95% and 19.07% with high V OC of 0.986 V, 0.973 V and 0.958 V, respectively. In addition, D18:L8‐BO:AQI13‐c‐based ternary OSCs realized an improved PCE of 20.20% in comparison with the binary device (PCE = 19.37%). This work offers a viable strategy for designing shamrock‐shaped NFAs for high‐voltage and high‐performance binary and ternary OSCs.