Non-Fully Conjugated Photovoltaic Materials with Y-Series Acceptor Backbone for High-Performance Organic Solar Cells

In the last few years, organic solar cells (OSCs) have made significant progress in photovoltaic performance, mainly due to the innovative development of active layer materials, especially Y-series and related derivatives as acceptors which have become the key factor that boosts the power conversion efficiency. Recently, to achieve high-performance OSCs, an emerging molecular design strategy of applying flexible alkyl units as linkers to construct non-fully conjugated acceptors has been developed and addressed great attention. This review highlights the non-fully conjugated photovoltaic materials with Y-series backbone that enable high-performance OSCs. Impressive OSCs have been achieved by some representative non-fully conjugated material systems. The related molecular design strategies are discussed in detail. Finally, a brief summary and future prospect are provided in advancing the non-fully conjugated photovoltaic materials with Y-series backbone towards the brighter future.