Effects of Anthryl Groups on the Charge Transport and Photovoltaic Properties of Small Triarylamine-Based Donor-Acceptor Molecules: A Joint Experimental and Theoretical Study

The effects of replacing one of the outer phenyl rings of triphenylamine by 2-anthryl and 9-anthryl groups of triphenylamine (TPA) have been investigated on two small push-pull molecules consisting of a triarylamine donor block connected to a dicyanovinyl acceptor via a thienyl spacer. UV-Vis absorption, cyclic voltammetry and theoretical calculations show that the mode of linkage of the anthryl group has a limited influence on the electronic properties of the molecule compared to reference compound based on TPA. However experimental and theoretical results show that this simple structural modification exerts a major impact on the hole-mobility of the resulting materials and thus on their efficiency as donor in planar heterojunction solar cells.