Latest progress on fully non‐fused electron acceptors for high‐performance organic solar cells

Benefitting from the development of non-fullerene acceptors (NFAs), remarkable advances have been achieved with the power conversion efficiency (PCE) exceeding 19% over the last few years. However, the major achievement comes from fused ring electron acceptors (FREAs) with complex structures, leading to high cost. Hence, it is urgent to design new materials to resolve the cost issues concerning basic commercial requirements of organic solar cells. Recently, great progress has been made in fully non-fused ring electron acceptors (NFREAs) with only single-aromatic ring in the electron-donating core, which might achieve a fine balance between the efficiency and cost, thus accelerating the commercial application of organic solar cells. Therefore, this article summarizes the recent advances of fully NFREAs with efficiency over 10%, which may provide a guidance for developing the cost-effective solar cells.