An A(2)-pi-A(1)-pi-A(2)-type small molecule donor for high-performance organic solar cells

摘要

A new A(2)--A(1)--A(2)-type small molecule denoted as BDD-IN was synthesized employing a strong electron-withdrawing unit, 3-bis(4-(2-ethylhexyl)-thiophen-2-yl)-5,7-bis(2-ethylhexyl)benzo[1,2:4,5-c]-dithiophene-4,8-dione (BDD) as the central acceptor unit (A(1)), thiophene-alkoxy benzene-thiophene as the -bridge, and indenedione (IN) as the end-capped unit (A(2)). An optimal power conversion efficiency (PCE) of 8.70% with a high open-circuit voltage (V-oc) of 0.965 V and a high fill factor (FF) of 72.3% was achieved.