A Benzo[1,2‐b:4,5‐c′]Dithiophene‐4,8‐Dione‐Based Polymer Donor Achieving an Efficiency Over 16%

It is of great significance to develop efficient donor polymers during the rapid development of acceptor materials for nonfullerene bulk‐heterojunction (BHJ) polymer solar cells. Herein, a new donor polymer, named PBTT‐F, based on a strongly electron‐deficient core (5,7‐dibromo‐2,3‐bis(2‐ethylhexyl)benzo[1,2‐ b :4,5‐ c ′]dithiophene‐4,8‐dione, TTDO), is developed through the design of cyclohexane‐1,4‐dione embedded into a thieno[3,4‐ b...