A Thieno3,2-cIsoquinolin-5(4H)-One Building Block for Efficient Thick-Film Solar Cells

摘要

An aromatic lactam acceptor unit, thieno3,2-cisoquinolin-5(4H)-one (TIQ), is developed. Compared with its analogues, dithieno3,2-b:2,3-dpyridin-5(4H)-one (DTP) and phenanthridin-6(5H)-one (PN), TIQ shows its advantage in constructing donor-acceptor (D-A) copolymers for efficient solar cells. TIQ-based D-A copolymer PTIQ4TFBT delivers a power conversion efficiency (PCE) of 10.16 in polymer:fullerene solar cells, while those based on DTP and PN copolymers, PDTP4TFBT and PPN4TFBT, afford PCEs around 8.5. The higher performance of PTIQ4TFBT:PC71BM solar cells originates from enhanced short-circuit current density (J(sc)) and fill factor (FF), because of favorable morphology, less bimolecular recombination, and balanced charge transport in the active layer. Moreover, the performance for PTIQ4TFBT:PC71BM solar cells is less sensitive to active layer thickness than PDTP4TFBT:PC71BM and PPN4TFBT:PC71BM solar cells. Over 8 PCEs can be obtained from PTIQ4TFBT:PC71BM solar cells when the active layer thickness is over 500 nm.