π-Extended low bandgap polymer based on isoindigo and thienylvinylene for high performance polymer solar cells†
Abstract
A π-extended low bandgap polymer (PiITVT) consisting of isoindigo and thienylvinylene is synthesized and used as an active layer material for polymer solar cells. PiITVT-based polymer solar cells exhibited a high power conversion efficiency of 7.09%, which is higher than that of PiI2T (5.55%), because of the better coplanar structure of the TVT unit than the 2T unit.