PY-IT,an Excellent Polymer Acceptor

All-polymer solar cells(all-PSCs)have attracted considerable attention due to their inherent advantages over other types of organic solar cells,including superior optical and thermal stability,as well as exceptional mechanical durability.Recently,all-PSCs have experienced remarkable advancements in device performance thanks to the invention of polymerized small-molecule acceptors(PSMAs)since 2017.Among these PSMAs,PY-IT has garnered immense interest from the scientific community due to its exceptional performance in all-PSCs.In this review,we presented the design principles of PY-IT and discussed the various strategies employed in device engineering for PY-IT-based all-PSCs.These strategies include additive and interface engineering,layer-by-layer processing methods,meniscus-assisted coating methods,and ternary strategy.Furthermore,this review highlighted several novel polymeric donor materials that are paired with PY-IT to achieve efficient all-PSCs.Lastly,we summarized the inspiring strategies for further advancing all-PSCs based on PY-IT.These strategies aim to enhance the overall performance and stability of all-PSCs by exploring new materials,optimizing device architectures,and improving fabrication techniques.By leveraging these approaches,we anticipate significant progress in the development of all-PSCs and their potential as a viable renewable energy source.