15% Efficiency All-Polymer Solar Cells Based on a Polymer Acceptor Containing B←N Unit

The development of new polymer acceptors strongly paves the power conversion efficiency (PCE) improvement of all polymer solar cells (all-PSCs). Herein, we develop a new polymer acceptor PBN26, which is the alternating copolymer of 2,2 '-((2Z,2 ' Z)-((12,13-bis(2-octyldodecyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2 '',3 '':4 ',5 ']thieno[2 ',3 ':4,5]pyrrolo[3,2-g]thieno[2 ',3 ':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1 H-indene-2,1-diylidene))dimalononitrile and B <- N bridged thienylthiazole (BNTT). The optimized all-PSCs device based on PBN26 exhibits a PCE of 15.09%, which is the highest value of the all-PSCs based on B <- N-based polymer acceptors at present. Moreover, we also fabricate an all-PSC module with active area of 10 cm(2) by blade coating, which exhibits a PCE of 8.78%. These results prove that polymer acceptors containing B <- N units are promising for all-PSC device applications.

Automated summary

The development of new polymer acceptors is crucial for improving the power conversion efficiency of all polymer solar cells. In this study, a new polymer acceptor called PBN26 was developed, and it achieved a PCE of 15.09%, which is the highest among all-PSCs based on B <- N-based polymer acceptors at present.