A zigzag fused-ring building block for polymer solar cells†
Abstract
Two D–A copolymers PThzTITI and PSezTITI, based on a zigzag fused-ring acceptor unit zTITI, were developed. They possess low HOMO energy levels around −5.6 eV. PSezTITI:PC71BM solar cells gave a power conversion efficiency (PCE) of 2.36%. All solar cells produced very high Voc up to 1.08 V.