화학공학소재연구정보센터
Macromolecular Rapid Communications, Vol.37, No.13, 1066-1073, 2016
Broad Bandgap D-A Copolymer Based on Bithiazole Acceptor Unit for Application in High-Performance Polymer Solar Cells with Lower Fullerene Content
A new broad bandgap and 2D-conjugated D-A copolymer, PBDTBTz-T, based on bithienyl-benzodithiophene donor unit and bithiazole (BTz) acceptor unit, is designed and synthesized for the application as donor material in polymer solar cells (PSCs). The polymer possesses highly coplanar and crystalline structure with a higher hole mobility and lower HOMO energy level which is beneficial to achieve higher open circuit voltage (V-oc) of the PSCs with the polymer as donor. The PSCs based on PBDTBTz-T:PC71BM blend film with a lower PC71BM content of 40% demonstrate a power conversion efficiency (PCE) of 6.09% with a relatively higher V-oc of 0.92 V. These results indicate that the lower HOMO energy level of the BTz-based D-A copolymer is beneficial to a high V-oc of the PSCs. The polymer, with highly coplanar and crystalline structure, can effectively reduce the content of fullerene acceptor in the active layer and can enhance the absorption and PCE of the PSCs.