Status and prospects of ternary all-polymer organic solar cells

All-polymer solar cells (all-PSCs) exhibit tremendous potential in fields such as smart and wearable electronic devices due to the benefits of low-cost, flexibility and large-area processability. Researches related to all-PSCs is mushrooming with the development of new polymeric donor and acceptor ma-terials and the continuous optimization of active layer morphology and device performance. It is imperative to further boost the performance of all-PSCs with more productive methods. Ternary blend strategy is widely considered as a straightforward and effective method to optimize the morphology, photovoltaic efficiency and stability. In this review, we present the recent progress in three kinds of ternary blend based all-PSCs, namely, dual-donor and dual-acceptor ternary all-PSCs and the introduc-tion of small-molecules in binary all-PSCs, and discuss in depth how the ternary strategy in all-PSCs can improve cell performance by optimizing film morphology and charge carrier transport properties, helping readers to better understand the morphology-efficiency/stability relationship. Simultaneously, we provide a concise discussion on the challenges and opportunities for the future development of ternary all-PSCs targeting 20% efficiency. (c) 2022 Elsevier Ltd. All rights reserved.